#METABOLOMICS WORKBENCH SBlab_20241229_225507 DATATRACK_ID:5495 STUDY_ID:ST003654 ANALYSIS_ID:AN006004 PROJECT_ID:PR002264
VERSION             	1
CREATED_ON             	January 8, 2025, 2:07 am
#PROJECT
PR:PROJECT_TITLE                 	Identifying the lipidomic signature from human blood reveals human sex.
PR:PROJECT_SUMMARY               	We used paper spray ionization mass spectrometry (PSI-MS) to develop a rapid
PR:PROJECT_SUMMARY               	reagent-free blood test for human sex identification by analyzing
PR:PROJECT_SUMMARY               	sex-discriminatory lipid profiles from 200 dried blood spot (DBS) samples
PR:PROJECT_SUMMARY               	comprising 100 males and 100 females. Following an in-house Python-based
PR:PROJECT_SUMMARY               	peak-picking program, we could identify 664 prominent peaks (m/z values) from
PR:PROJECT_SUMMARY               	the TIC (Total Ion Current) normalized positive ion mode PSI-MS dataset
PR:PROJECT_SUMMARY               	comprised of all DBS samples on paper. We performed a supervised machine
PR:PROJECT_SUMMARY               	learning analysis on all detected lipid signals to identify sex biomarkers
PR:PROJECT_SUMMARY               	within the dataset. This study revealed significant differences in the level of
PR:PROJECT_SUMMARY               	specific sphingomyelin and phospholipid species between male and female DBS
PR:PROJECT_SUMMARY               	samples.
PR:INSTITUTE                     	Indian Institute of Science Education and Research Tirupati
PR:DEPARTMENT                    	Chemistry
PR:LABORATORY                    	SBlab
PR:LAST_NAME                     	Mondal
PR:FIRST_NAME                    	Supratim
PR:ADDRESS                       	Venkatagiri Road, Yerpedu Mandal, Tirupati, Andhra Pradesh - 517619, India
PR:EMAIL                         	supratimmondal@students.iisertirupati.ac.in
PR:PHONE                         	9051034727
#STUDY
ST:STUDY_TITLE                   	Rapid and Reagent-free Analysis of Dried Blood Spot by Paper Spray Mass
ST:STUDY_TITLE                   	Spectrometry Reveals Sex: Implications in Forensic Investigations.
ST:STUDY_SUMMARY                 	Identifying sex from an unknown dried blood spot (DBS), especially when the
ST:STUDY_SUMMARY                 	corpse remains undiscovered, often provides valuable evidence in forensic
ST:STUDY_SUMMARY                 	casework. While DNA-based sex determination is a reliable method in forensic
ST:STUDY_SUMMARY                 	settings, it requires ex-pensive reagents and is time-consuming. To develop a
ST:STUDY_SUMMARY                 	rapid reagent-free blood test for sex, we employed paper spray ionization mass
ST:STUDY_SUMMARY                 	spectrometry (PSI-MS) to capture sex-discriminatory lipid profiles from 200 DBS
ST:STUDY_SUMMARY                 	samples comprising 100 males and 100 females. We conducted a supervised machine
ST:STUDY_SUMMARY                 	learning (ML) analysis on all detected lipid signals to hunt biomarkers of sex
ST:STUDY_SUMMARY                 	within the dataset. This analysis unveiled significant differences in specific
ST:STUDY_SUMMARY                 	sphingomyelin and phospholipid species levels between male and female DBS
ST:STUDY_SUMMARY                 	samples. Using the parsimonious set of 60 lipid signals, we constructed a
ST:STUDY_SUMMARY                 	classifier that achieved 100% overall accuracy in predicting sex from DBS on
ST:STUDY_SUMMARY                 	paper. Additionally, we assessed three-day-old air-exposed DBS on glass and
ST:STUDY_SUMMARY                 	granite surfaces, simulating the typical blood samples available for forensic
ST:STUDY_SUMMARY                 	investigations. Consequently, we achieved ~92% overall sex prediction accuracy
ST:STUDY_SUMMARY                 	from the holdout test dataset of DBS on glass and granite surfaces. As a highly
ST:STUDY_SUMMARY                 	sensitive detection tool, PSI-MS combined with ML has the potential to
ST:STUDY_SUMMARY                 	revolutionize forensic methods by rapidly analyzing blood molecules encoding
ST:STUDY_SUMMARY                 	personal information.
ST:INSTITUTE                     	Indian Institute of Science Education and Research Tirupati
ST:DEPARTMENT                    	Chemistry
ST:LABORATORY                    	SBlab
ST:LAST_NAME                     	Mondal
ST:FIRST_NAME                    	Supratim
ST:ADDRESS                       	Venkatagiri Road, Yerpedu Mandal, Tirupati, Andhra Pradesh - 517619, India
ST:EMAIL                         	supratimmondal@students.iisertirupati.ac.in
ST:PHONE                         	9051034727
ST:TOTAL_SUBJECTS                	200
ST:NUM_MALES                     	100
ST:NUM_FEMALES                   	100
#SUBJECT
SU:SUBJECT_TYPE                  	Human
SU:SUBJECT_SPECIES               	Homo sapiens
SU:TAXONOMY_ID                   	9606
SU:GENDER                        	Male and female
#SUBJECT_SAMPLE_FACTORS:         	SUBJECT(optional)[tab]SAMPLE[tab]FACTORS(NAME:VALUE pairs separated by |)[tab]Raw file names and additional sample data
SUBJECT_SAMPLE_FACTORS           	H1	HF1	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF1.mzML
SUBJECT_SAMPLE_FACTORS           	H2	HF2	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF2.mzML
SUBJECT_SAMPLE_FACTORS           	H3	HF3	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF3.mzML
SUBJECT_SAMPLE_FACTORS           	H4	HF4	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF4.mzML
SUBJECT_SAMPLE_FACTORS           	H5	HF5	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF5.mzML
SUBJECT_SAMPLE_FACTORS           	H6	HF6	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF6.mzML
SUBJECT_SAMPLE_FACTORS           	H7	HF7	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF7.mzML
SUBJECT_SAMPLE_FACTORS           	H8	HF8	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF8.mzML
SUBJECT_SAMPLE_FACTORS           	H9	HF9	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF9.mzML
SUBJECT_SAMPLE_FACTORS           	H10	HF10	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF10.mzML
SUBJECT_SAMPLE_FACTORS           	H11	HF11	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF11.mzML
SUBJECT_SAMPLE_FACTORS           	H12	HF12	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF12.mzML
SUBJECT_SAMPLE_FACTORS           	H13	HF13	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF13.mzML
SUBJECT_SAMPLE_FACTORS           	H14	HF14	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF14.mzML
SUBJECT_SAMPLE_FACTORS           	H15	HF15	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF15.mzML
SUBJECT_SAMPLE_FACTORS           	H16	HF16	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF16.mzML
SUBJECT_SAMPLE_FACTORS           	H17	HF17	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF17.mzML
SUBJECT_SAMPLE_FACTORS           	H18	HF18	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF18.mzML
SUBJECT_SAMPLE_FACTORS           	H19	HF19	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF19.mzML
SUBJECT_SAMPLE_FACTORS           	H20	HF20	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF20.mzML
SUBJECT_SAMPLE_FACTORS           	H21	HF21	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF21.mzML
SUBJECT_SAMPLE_FACTORS           	H22	HF22	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF22.mzML
SUBJECT_SAMPLE_FACTORS           	H23	HF23	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF23.mzML
SUBJECT_SAMPLE_FACTORS           	H24	HF24	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF24.mzML
SUBJECT_SAMPLE_FACTORS           	H25	HF25	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF25.mzML
SUBJECT_SAMPLE_FACTORS           	H26	HF26	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF26.mzML
SUBJECT_SAMPLE_FACTORS           	H27	HF27	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF27.mzML
SUBJECT_SAMPLE_FACTORS           	H28	HF28	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF28.mzML
SUBJECT_SAMPLE_FACTORS           	H29	HF29	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF29.mzML
SUBJECT_SAMPLE_FACTORS           	H30	HF30	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF30.mzML
SUBJECT_SAMPLE_FACTORS           	H31	HF31	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF31.mzML
SUBJECT_SAMPLE_FACTORS           	H32	HF32	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF32.mzML
SUBJECT_SAMPLE_FACTORS           	H33	HF33	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF33.mzML
SUBJECT_SAMPLE_FACTORS           	H34	HF34	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF34.mzML
SUBJECT_SAMPLE_FACTORS           	H35	HF35	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF35.mzML
SUBJECT_SAMPLE_FACTORS           	H36	HF36	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF36.mzML
SUBJECT_SAMPLE_FACTORS           	H37	HF37	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF37.mzML
SUBJECT_SAMPLE_FACTORS           	H38	HF38	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF38.mzML
SUBJECT_SAMPLE_FACTORS           	H39	HF39	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF39.mzML
SUBJECT_SAMPLE_FACTORS           	H40	HF40	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF40.mzML
SUBJECT_SAMPLE_FACTORS           	H41	HF41	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF41.mzML
SUBJECT_SAMPLE_FACTORS           	H42	HF42	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF42.mzML
SUBJECT_SAMPLE_FACTORS           	H43	HF43	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF43.mzML
SUBJECT_SAMPLE_FACTORS           	H44	HF44	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF44.mzML
SUBJECT_SAMPLE_FACTORS           	H45	HF45	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF45.mzML
SUBJECT_SAMPLE_FACTORS           	H46	HF46	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF46.mzML
SUBJECT_SAMPLE_FACTORS           	H47	HF47	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF47.mzML
SUBJECT_SAMPLE_FACTORS           	H48	HF48	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF48.mzML
SUBJECT_SAMPLE_FACTORS           	H49	HF49	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF49.mzML
SUBJECT_SAMPLE_FACTORS           	H50	HF50	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF50.mzML
SUBJECT_SAMPLE_FACTORS           	H51	HF51	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF51.mzML
SUBJECT_SAMPLE_FACTORS           	H52	HF52	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF52.mzML
SUBJECT_SAMPLE_FACTORS           	H53	HF53	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF53.mzML
SUBJECT_SAMPLE_FACTORS           	H54	HF54	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF54.mzML
SUBJECT_SAMPLE_FACTORS           	H55	HF55	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF55.mzML
SUBJECT_SAMPLE_FACTORS           	H56	HF56	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF56.mzML
SUBJECT_SAMPLE_FACTORS           	H57	HF57	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF57.mzML
SUBJECT_SAMPLE_FACTORS           	H58	HF58	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF58.mzML
SUBJECT_SAMPLE_FACTORS           	H59	HF59	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF59.mzML
SUBJECT_SAMPLE_FACTORS           	H60	HF60	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF60.mzML
SUBJECT_SAMPLE_FACTORS           	H61	HF61	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF61.mzML
SUBJECT_SAMPLE_FACTORS           	H62	HF62	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF62.mzML
SUBJECT_SAMPLE_FACTORS           	H63	HF63	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF63.mzML
SUBJECT_SAMPLE_FACTORS           	H64	HF64	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF64.mzML
SUBJECT_SAMPLE_FACTORS           	H65	HF65	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF65.mzML
SUBJECT_SAMPLE_FACTORS           	H66	HF66	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF66.mzML
SUBJECT_SAMPLE_FACTORS           	H67	HF67	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF67.mzML
SUBJECT_SAMPLE_FACTORS           	H68	HF68	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF68.mzML
SUBJECT_SAMPLE_FACTORS           	H69	HF69	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF69.mzML
SUBJECT_SAMPLE_FACTORS           	H70	HF70	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF70.mzML
SUBJECT_SAMPLE_FACTORS           	H71	HF71_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF71_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H72	HF72_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF72_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H73	HF73_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF73_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H74	HF74_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF74_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H75	HF75_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF75_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H76	HF76_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF76_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H77	HF77_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF77_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H78	HF78_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF78_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H79	HF79_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF79_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H80	HF80_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF80_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H81	HF81_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF81_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H82	HF82_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF82_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H83	HF83_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF83_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H84	HF84_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF84_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H85	HF85_glass	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF85_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H86	HF86_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF86_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H87	HF87_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF87_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H88	HF88_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF88_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H89	HF89_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF89_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H90	HF90_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF90_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H91	HF91_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF91_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H92	HF92_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF92_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H93	HF93_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF93_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H94	HF94_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF94_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H95	HF95_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF95_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H96	HF96_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF96_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H97	HF97_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF97_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H98	HF98_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF98_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H99	HF99_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF99_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H100	HF100_granite	Sample source:Blood | Sex:Female	RAW_FILE_NAME=HF100_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H101	HM1	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM1.mzML
SUBJECT_SAMPLE_FACTORS           	H102	HM2	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM2.mzML
SUBJECT_SAMPLE_FACTORS           	H103	HM3	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM3.mzML
SUBJECT_SAMPLE_FACTORS           	H104	HM4	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM4.mzML
SUBJECT_SAMPLE_FACTORS           	H105	HM5	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM5.mzML
SUBJECT_SAMPLE_FACTORS           	H106	HM6	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM6.mzML
SUBJECT_SAMPLE_FACTORS           	H107	HM7	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM7.mzML
SUBJECT_SAMPLE_FACTORS           	H108	HM8	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM8.mzML
SUBJECT_SAMPLE_FACTORS           	H109	HM9	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM9.mzML
SUBJECT_SAMPLE_FACTORS           	H110	HM10	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM10.mzML
SUBJECT_SAMPLE_FACTORS           	H111	HM11	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM11.mzML
SUBJECT_SAMPLE_FACTORS           	H112	HM12	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM12.mzML
SUBJECT_SAMPLE_FACTORS           	H113	HM13	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM13.mzML
SUBJECT_SAMPLE_FACTORS           	H114	HM14	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM14.mzML
SUBJECT_SAMPLE_FACTORS           	H115	HM15	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM15.mzML
SUBJECT_SAMPLE_FACTORS           	H116	HM16	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM16.mzML
SUBJECT_SAMPLE_FACTORS           	H117	HM17	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM17.mzML
SUBJECT_SAMPLE_FACTORS           	H118	HM18	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM18.mzML
SUBJECT_SAMPLE_FACTORS           	H119	HM19	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM19.mzML
SUBJECT_SAMPLE_FACTORS           	H120	HM20	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM20.mzML
SUBJECT_SAMPLE_FACTORS           	H121	HM21	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM21.mzML
SUBJECT_SAMPLE_FACTORS           	H122	HM22	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM22.mzML
SUBJECT_SAMPLE_FACTORS           	H123	HM23	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM23.mzML
SUBJECT_SAMPLE_FACTORS           	H124	HM24	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM24.mzML
SUBJECT_SAMPLE_FACTORS           	H125	HM25	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM25.mzML
SUBJECT_SAMPLE_FACTORS           	H126	HM26	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM26.mzML
SUBJECT_SAMPLE_FACTORS           	H127	HM27	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM27.mzML
SUBJECT_SAMPLE_FACTORS           	H128	HM28	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM28.mzML
SUBJECT_SAMPLE_FACTORS           	H129	HM29	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM29.mzML
SUBJECT_SAMPLE_FACTORS           	H130	HM30	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM30.mzML
SUBJECT_SAMPLE_FACTORS           	H131	HM31	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM31.mzML
SUBJECT_SAMPLE_FACTORS           	H132	HM32	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM32.mzML
SUBJECT_SAMPLE_FACTORS           	H133	HM33	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM33.mzML
SUBJECT_SAMPLE_FACTORS           	H134	HM34	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM34.mzML
SUBJECT_SAMPLE_FACTORS           	H135	HM35	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM35.mzML
SUBJECT_SAMPLE_FACTORS           	H136	HM36	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM36.mzML
SUBJECT_SAMPLE_FACTORS           	H137	HM37	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM37.mzML
SUBJECT_SAMPLE_FACTORS           	H138	HM38	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM38.mzML
SUBJECT_SAMPLE_FACTORS           	H139	HM39	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM39.mzML
SUBJECT_SAMPLE_FACTORS           	H140	HM40	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM40.mzML
SUBJECT_SAMPLE_FACTORS           	H141	HM41	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM41.mzML
SUBJECT_SAMPLE_FACTORS           	H142	HM42	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM42.mzML
SUBJECT_SAMPLE_FACTORS           	H143	HM43	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM43.mzML
SUBJECT_SAMPLE_FACTORS           	H144	HM44	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM44.mzML
SUBJECT_SAMPLE_FACTORS           	H145	HM45	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM45.mzML
SUBJECT_SAMPLE_FACTORS           	H146	HM46	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM46.mzML
SUBJECT_SAMPLE_FACTORS           	H147	HM47	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM47.mzML
SUBJECT_SAMPLE_FACTORS           	H148	HM48	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM48.mzML
SUBJECT_SAMPLE_FACTORS           	H149	HM49	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM49.mzML
SUBJECT_SAMPLE_FACTORS           	H150	HM50	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM50.mzML
SUBJECT_SAMPLE_FACTORS           	H151	HM51	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM51.mzML
SUBJECT_SAMPLE_FACTORS           	H152	HM52	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM52.mzML
SUBJECT_SAMPLE_FACTORS           	H153	HM53	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM53.mzML
SUBJECT_SAMPLE_FACTORS           	H154	HM54	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM54.mzML
SUBJECT_SAMPLE_FACTORS           	H155	HM55	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM55.mzML
SUBJECT_SAMPLE_FACTORS           	H156	HM56	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM56.mzML
SUBJECT_SAMPLE_FACTORS           	H157	HM57	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM57.mzML
SUBJECT_SAMPLE_FACTORS           	H158	HM58	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM58.mzML
SUBJECT_SAMPLE_FACTORS           	H159	HM59	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM59.mzML
SUBJECT_SAMPLE_FACTORS           	H160	HM60	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM60.mzML
SUBJECT_SAMPLE_FACTORS           	H161	HM61	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM61.mzML
SUBJECT_SAMPLE_FACTORS           	H162	HM62	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM62.mzML
SUBJECT_SAMPLE_FACTORS           	H163	HM63	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM63.mzML
SUBJECT_SAMPLE_FACTORS           	H164	HM64	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM64.mzML
SUBJECT_SAMPLE_FACTORS           	H165	HM65	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM65.mzML
SUBJECT_SAMPLE_FACTORS           	H166	HM66	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM66.mzML
SUBJECT_SAMPLE_FACTORS           	H167	HM67	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM67.mzML
SUBJECT_SAMPLE_FACTORS           	H168	HM68	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM68.mzML
SUBJECT_SAMPLE_FACTORS           	H169	HM69	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM69.mzML
SUBJECT_SAMPLE_FACTORS           	H170	HM70	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM70.mzML
SUBJECT_SAMPLE_FACTORS           	H171	HM71_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM71_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H172	HM72_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM72_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H173	HM73_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM73_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H174	HM74_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM74_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H175	HM75_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM75_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H176	HM76_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM76_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H177	HM77_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM77_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H178	HM78_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM78_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H179	HM79_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM79_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H180	HM80_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM80_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H181	HM81_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM81_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H182	HM82_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM82_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H183	HM83_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM83_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H184	HM84_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM84_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H185	HM85_glass	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM85_glass.mzML
SUBJECT_SAMPLE_FACTORS           	H186	HM86_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM86_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H187	HM87_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM87_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H188	HM88_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM88_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H189	HM89_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM89_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H190	HM90_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM90_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H191	HM91_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM91_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H192	HM92_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM92_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H193	HM93_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM93_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H194	HM94_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM94_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H195	HM95_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM95_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H196	HM96_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM96_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H197	HM97_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM97_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H198	HM98_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM98_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H199	HM99_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM99_granite.mzML
SUBJECT_SAMPLE_FACTORS           	H200	HM100_granite	Sample source:Blood | Sex:Male	RAW_FILE_NAME=HM100_granite.mzML
#COLLECTION
CO:COLLECTION_SUMMARY            	We have collected finger-pricked blood from 200 volunteers (human participants)
CO:COLLECTION_SUMMARY            	following the approval of the Human Ethics Committee and Institution Review
CO:COLLECTION_SUMMARY            	Board (IRB). The left index fingers of all volunteers (human participants) were
CO:COLLECTION_SUMMARY            	cleaned with the hand-rubbing alcoholic solution and dried in air for one minute
CO:COLLECTION_SUMMARY            	prior to the blood collection. The finger was pricked using a commercially
CO:COLLECTION_SUMMARY            	available lancing device pen with sterile disposable lancet needles. The freshly
CO:COLLECTION_SUMMARY            	come-out fingerprick blood was immediately spotted on the previously incised
CO:COLLECTION_SUMMARY            	triangular (isosceles with 10 mm in height and 5 mm in the base) Whatman filter
CO:COLLECTION_SUMMARY            	paper (grade 1) and kept for drying in the open air for 5 min followed by
CO:COLLECTION_SUMMARY            	preserving in a tightly sealed container at 4 oC. Thus, 140 human dried blood
CO:COLLECTION_SUMMARY            	spot (DBS) samples were collected directly on the paper. Analogously, another
CO:COLLECTION_SUMMARY            	set of blood spots was collected from 60 volunteers (30 males and 30 females) on
CO:COLLECTION_SUMMARY            	two other solid surfaces, such as glass and granite, which were then kept for
CO:COLLECTION_SUMMARY            	drying in the open air and at room temperature for three days before extracting
CO:COLLECTION_SUMMARY            	for MS study.
CO:SAMPLE_TYPE                   	Blood (whole)
CO:COLLECTION_METHOD             	Dried blood spot from finger prick blood drop
CO:STORAGE_CONDITIONS            	4℃
#TREATMENT
TR:TREATMENT_SUMMARY             	No further post-sampling treatment was performed with the dried blood spot (DBS)
TR:TREATMENT_SUMMARY             	samples. The collected DBS were directly sprayed toward the MS inlet capillary
TR:TREATMENT_SUMMARY             	following the paper spray ionization technique.
#SAMPLEPREP
SP:SAMPLEPREP_SUMMARY            	No further steps of sample pre-treatment/preparation were followed for the dried
SP:SAMPLEPREP_SUMMARY            	blood spot (DBS) collected on the paper sample. However, the DBS collected from
SP:SAMPLEPREP_SUMMARY            	other solid surfaces (e.g. glass or granite) encounters another step of the
SP:SAMPLEPREP_SUMMARY            	sample preparation. Such DBS samples were extracted in approximately 200 µL of
SP:SAMPLEPREP_SUMMARY            	methanol (MeOH) containing 0.1% formic acid (HCOOH) solution using a pipette. In
SP:SAMPLEPREP_SUMMARY            	this extraction process, the above methanolic solvent was dispensed onto the
SP:SAMPLEPREP_SUMMARY            	dried blood spot. The spot was then allowed to swell for a couple of minutes.
SP:SAMPLEPREP_SUMMARY            	After that, the liquid above the spot was repeatedly pipetted in and out
SP:SAMPLEPREP_SUMMARY            	multiple times (at least five times) to extract the blood lipids/metabolites in
SP:SAMPLEPREP_SUMMARY            	methanol while keeping blood cells insoluble. Thus, the ex-tracted methanolic
SP:SAMPLEPREP_SUMMARY            	solutions from individual blood samples were collected in microcentrifuge tubes
SP:SAMPLEPREP_SUMMARY            	for aliquoting (15 µL) on the triangular Whatman filter papers followed by
SP:SAMPLEPREP_SUMMARY            	PSI-MS analysis.
SP:PROCESSING_STORAGE_CONDITIONS 	4℃
SP:EXTRACT_STORAGE               	4℃
#CHROMATOGRAPHY
CH:CHROMATOGRAPHY_TYPE           	None (Direct infusion)
CH:INSTRUMENT_NAME               	none
CH:COLUMN_NAME                   	none
CH:SOLVENT_A                     	none
CH:SOLVENT_B                     	none
CH:FLOW_GRADIENT                 	none
CH:FLOW_RATE                     	none
CH:COLUMN_TEMPERATURE            	none
#ANALYSIS
AN:ANALYSIS_TYPE                 	MS
AN:LABORATORY_NAME               	SBlab
AN:OPERATOR_NAME                 	Supratim Mondal
#MS
MS:INSTRUMENT_NAME               	Thermo Orbitrap Elite Hybrid Ion Trap-Orbitrap
MS:INSTRUMENT_TYPE               	Orbitrap
MS:MS_TYPE                       	PSI
MS:ION_MODE                      	POSITIVE
MS:MS_COMMENTS                   	All the dried blood spot (DBS) samples were considered for paper spray
MS:MS_COMMENTS                   	ionization mass spectrometry (PSI-MS) scanning under positive ion mode. The MS
MS:MS_COMMENTS                   	data were extracted from each .raw file by averaging the scans over a time of
MS:MS_COMMENTS                   	1-minute data recording. All mass spectral data were subjected to the total ion
MS:MS_COMMENTS                   	current (TIC) and mean normalization method to surpass any random effect that
MS:MS_COMMENTS                   	could influence the data and make samples comparable. Since there was no
MS:MS_COMMENTS                   	noticeable spectral difference between the average spectra (across all samples)
MS:MS_COMMENTS                   	resulting from TIC and mean normalized data in each group (data not shown), we
MS:MS_COMMENTS                   	opted to consider the TIC normalized (a widely used normalization method) data
MS:MS_COMMENTS                   	only for further data processing and analysis. In total, we collected 200 MS
MS:MS_COMMENTS                   	data from different samples. In the initial phase, 140 TIC-normalized PSI-MS
MS:MS_COMMENTS                   	data obtained from direct DBS on paper (70 male and 70 female candidates) were
MS:MS_COMMENTS                   	divided randomly into two sets using random stratified sampling. The first set
MS:MS_COMMENTS                   	(Set-I) comprised 112 samples (56 males and 56 females). Set-I data were used to
MS:MS_COMMENTS                   	pinpoint the most prominent signals (peaks) in the MS dataset and determine the
MS:MS_COMMENTS                   	most important features (peaks) for building the machine learning (ML) model.
MS:MS_COMMENTS                   	The second set (Set-II) consists of the remaining 28 samples (14 males and 14
MS:MS_COMMENTS                   	females), which were separated and kept as a holdout test set to evaluate the
MS:MS_COMMENTS                   	performances of the final machine learning models at a later stage. In the
MS:MS_COMMENTS                   	second phase, 60 TIC-normalized PSI-MS data (30 males and 30 females) obtained
MS:MS_COMMENTS                   	from dried blood on other solid surfaces (glass and granite) were included to
MS:MS_COMMENTS                   	develop another ML classifier. Following the similar stratified sampling scheme
MS:MS_COMMENTS                   	used for the DBS on paper samples, these samples were randomly partitioned into
MS:MS_COMMENTS                   	two sets. At first, 48 samples (24 male and 24 female) were sorted following
MS:MS_COMMENTS                   	stratified sampling and referred to as Set-III. The remaining 12 samples (6
MS:MS_COMMENTS                   	males and 6 females) were considered for another holdout test set and labeled as
MS:MS_COMMENTS                   	Set-IV. Thus, another ML model was built using the Set-I and Set-III samples,
MS:MS_COMMENTS                   	considering the previously identified features from Set-I and Set-II. The
MS:MS_COMMENTS                   	performance of this model was then evaluated using the Set-II and Set-IV samples
MS:MS_COMMENTS                   	as holdout test sets. Peak picking Each TIC normalized mass spectrum comprised
MS:MS_COMMENTS                   	hundreds to thousands of ion signals within the m/z range of 150-1000. However,
MS:MS_COMMENTS                   	most of these signals appeared to have very low intensity and were considered
MS:MS_COMMENTS                   	noise signals. Thus, we employed an in-house Python program to remove noises and
MS:MS_COMMENTS                   	find the most prominent peaks in the MS dataset, as described below. At first,
MS:MS_COMMENTS                   	the entire m/z range (150 to 1000) for each MS data in Set-I was divided into
MS:MS_COMMENTS                   	equidistant bins (Δm/z) of width 0.05 m/z. The signal with the highest
MS:MS_COMMENTS                   	intensity in each bin was located, and the corresponding m/z values were stored.
MS:MS_COMMENTS                   	Then, the most probable position (m/z value) of the most intense signal inside a
MS:MS_COMMENTS                   	bin for all MS spectra in Set-I was determined using the following ways: Only
MS:MS_COMMENTS                   	those MS samples for a bin were considered for which the maximum intensities
MS:MS_COMMENTS                   	were higher than a cutoff value. This cutoff value in a bin was defined as the
MS:MS_COMMENTS                   	average value of the median and the mean of the maximum height (intensity value)
MS:MS_COMMENTS                   	for that particular bin across all the samples in Set-I. In the next step, the
MS:MS_COMMENTS                   	most prominent peak positions were obtained from the distribution of the
MS:MS_COMMENTS                   	positions (m/z values) of the maximum intensities in each bin from those MS
MS:MS_COMMENTS                   	samples satisfying the abovementioned criteria. However, in some cases, more
MS:MS_COMMENTS                   	than one peak was found to be present in a single bin. In that case, the second
MS:MS_COMMENTS                   	peak was only considered if the distribution height for the second peak was at
MS:MS_COMMENTS                   	least 60% of the most prominent peak. Two peaks found within the 0.02 m/z range
MS:MS_COMMENTS                   	were considered to be a single peak, and its position was recalculated as the
MS:MS_COMMENTS                   	mean of the peak positions within the 0.02 m/z interval. This resulted in a
MS:MS_COMMENTS                   	large number of peak positions (11,000). However, most of the peak positions
MS:MS_COMMENTS                   	(m/z) appeared as noises and had very low signal intensities. Those m/z values
MS:MS_COMMENTS                   	were removed from the list of prominent peaks following the procedure described
MS:MS_COMMENTS                   	below. The maximum intensities for the selected peak positions (11,000) were
MS:MS_COMMENTS                   	determined within the ±0.01 m/z for all MS samples in Set-I. A given peak
MS:MS_COMMENTS                   	position was considered to be a prominent peak if, at least for five spectra in
MS:MS_COMMENTS                   	Set-I, the maximum intensities of that specific peak were higher than 5⨉10-5
MS:MS_COMMENTS                   	(baseline). This constraint reduced the number of prominent peaks to 1753. These
MS:MS_COMMENTS                   	1753 peaks were further examined by plotting all Set-I spectra for each
MS:MS_COMMENTS                   	prominent peak, for some of the broad peaks that were assigned more than once in
MS:MS_COMMENTS                   	consecutive two or three bins were corrected. The baseline was too high for some
MS:MS_COMMENTS                   	peaks to be comparable with the selected peak. Those peaks were excluded, and
MS:MS_COMMENTS                   	finally, only 664 peaks were chosen as the most prominent peaks in the Set-I
MS:MS_COMMENTS                   	dataset. Feature selection The discriminatory peaks are those features (peaks)
MS:MS_COMMENTS                   	that can be used to classify a sample belonging to a particular cohort. Maximum
MS:MS_COMMENTS                   	intensities for the selected 664 peaks across all Set-I samples were determined
MS:MS_COMMENTS                   	within the ±Δx m/z. As the width of the ion signals increases with the
MS:MS_COMMENTS                   	increase of m/z value, Δx was expressed as a function of m/z (x), which
MS:MS_COMMENTS                   	linearly increases from 0.005 at 150 m/z to 0.02 at 1000 m/z and written as
MS:MS_COMMENTS                   	Δx(x) =0.005 + 0.015 * (x-150)/1000 . The importance score of each of these 664
MS:MS_COMMENTS                   	selected peaks was computed by constructing a binary classification model using
MS:MS_COMMENTS                   	the extra trees classifier (ETC) supervised learning algorithm. The
MS:MS_COMMENTS                   	‘ExtraTreeClassifier’ class, as defined in the scikit-learn package, was
MS:MS_COMMENTS                   	used in this work. The number of trees in the ETC model was 16, and the maximum
MS:MS_COMMENTS                   	depth was 8. The ETC model was trained 20,000 times using randomly selected 80
MS:MS_COMMENTS                   	peaks/features each time. Set-I MS data were used for training and validation
MS:MS_COMMENTS                   	purposes of the ETC model. In each iteration, the ETC model was initiated
MS:MS_COMMENTS                   	randomly, and each time, the Set-I samples were randomly divided into training
MS:MS_COMMENTS                   	and validation sets in a 4:1 ratio. The importance scores of the input features
MS:MS_COMMENTS                   	(prominent peaks) were computed and stored only when the model achieved good
MS:MS_COMMENTS                   	accuracy in training and validation sets (> 95% for the training set and > 85%
MS:MS_COMMENTS                   	for the validation set). The normalized feature importances obtained following
MS:MS_COMMENTS                   	the abovementioned procedure are listed for all 664 prominent peaks in Table 3
MS:MS_COMMENTS                   	of the PSIMSresults file. Here, it is worth mentioning that during the training
MS:MS_COMMENTS                   	of the models, the input features were standardized using the training data and
MS:MS_COMMENTS                   	following the standard procedure: xij = (xij - 𝜇j)/𝜎j, where xij is the
MS:MS_COMMENTS                   	value of the j-th feature for the i-th sample, 𝜇j is the mean value of the
MS:MS_COMMENTS                   	j-th feature and 𝜎j is the standard deviation of the j-th feature. Machine
MS:MS_COMMENTS                   	learning To classify the MS dataset, ML classification models were constructed
MS:MS_COMMENTS                   	using the support vector machine (SVM) supervised learning algorithm using the
MS:MS_COMMENTS                   	top 60 important signals (based on feature importance). The support vector
MS:MS_COMMENTS                   	classification (SVC) method, as implemented in the scikit-learn package, was
MS:MS_COMMENTS                   	used in this analysis. It uses the LIBSVM library. The radial basis function
MS:MS_COMMENTS                   	(RBF) was chosen as the kernel function for the SVC model. The RBF kernel
MS:MS_COMMENTS                   	hyperparameter ‘γ’ (gamma) and regularization parameter ‘C’ were
MS:MS_COMMENTS                   	optimized by running several times with different values. Finally, the values
MS:MS_COMMENTS                   	for γ and C were set at 0.015 and 10. Set-I data were randomly divided into
MS:MS_COMMENTS                   	training and validation sets following a stratified sampling scheme with a 4:1
MS:MS_COMMENTS                   	ratio and used for model training and validation purposes. Set-II (14 males and
MS:MS_COMMENTS                   	14 females) data, i.e., the holdout test set, was used for performance
MS:MS_COMMENTS                   	measurement of the optimized ML models. The procedure was repeated 1000 times.
MS:MS_COMMENTS                   	The ML model shows the highest prediction accuracy in classifying the MS samples
MS:MS_COMMENTS                   	and is considered the best SVM-based ML model. The best SVM model obtained from
MS:MS_COMMENTS                   	the abovementioned procedure was subjected to retraining using Set-I and Set-III
MS:MS_COMMENTS                   	data based on those top 60 important features to classify the dried blood
MS:MS_COMMENTS                   	samples obtained from different solid surfaces (Set-III and Set-IV). Therefore,
MS:MS_COMMENTS                   	the new SVM model was optimized using the samples, including Set-I and Set-III.
MS:MS_COMMENTS                   	Stratified sampling was used to divide the samples into training and validation
MS:MS_COMMENTS                   	sets to avoid class imbalances in the dataset. Thus, in total, 130 samples (90
MS:MS_COMMENTS                   	samples from Set-I and 40 samples from Set-III) were used for training, and 30
MS:MS_COMMENTS                   	samples (22 samples from Set-I and 8 samples from Set-III) were used for
MS:MS_COMMENTS                   	validation purposes. Classification results from the best-optimized model are
MS:MS_COMMENTS                   	reported in Tables 4-6 of the PSIMSresults file for the training, validation,
MS:MS_COMMENTS                   	and test sets, respectively.
MS:CAPILLARY_TEMPERATURE         	300 degrees Celsius
MS:ION_SPRAY_VOLTAGE             	+5kV
MS:MASS_ACCURACY                 	5ppm
MS:MS_RESULTS_FILE               	ST003654_AN006004_Results.txt	UNITS:Total ion current normalized intensity	Has m/z:Yes	Has RT:No	RT units:No RT data
#END