Methods

Key data of our analytical platforms are described below and include PubChem numbers, reported biomarker concentrations, LODs, CVs, ICCs, sample matrix and method description for most of our biomarkers.*

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Analytical platforms

Short-chain fatty acids.
GC-MS/MS: 50 µL vol.

All concentrations are reported in µmol/L.


Acetate	Ace	Short-chain fatty acid	175-176	5-300	s, p
Butyrate	But	Short-chain fatty acid	264	1-30	s, p
Formate	Frm	Short-chain fatty acid	284	8-100	s, p, csf
Isobutyrate	iBut	Short-chain fatty acid	6590	0.7-6	s, p, csf
Isovalerate	iVlr	Short-chain fatty acid	10430	0.3-3	s, p
Propionate	Pro	Short-chain fatty acid	1042	1-13	s, p
Valerate	Vlr	Short-chain fatty acid	7991	0.2-1	s, p
α-Methylbutyrate	aMB	Short-chain fatty acid	8314	0.3-3	s, p

Amino- and carboxylic acids. TCA metabolites and intermediates.
GC-MS/MS: 50 µL vol.

All concentrations are reported in µmol/L.


Methylmalonic acid	MMA	Carboxylic acid	487	<0.26	0.03	2.4	3	0.81	s, p
Total homocysteine	tHcy	Sulfur amino acid	91552	5-15	0.1	1.4	2.7	0.72	s, p
Total cysteine	tCys	Sulfur amino acid	5862	150-350	50	1	2	0.62	s, p
Methionine	Met	Essential amino acid	6137	18-50	1	2.2	4.1	0.33	s, p
Serine	Ser	Polar amino acid	5951	95-200	5	1.3	1.7	0.71	s, p
Glycine	Gly	Hydrophobic amino acid	750	150-350	3	1.3	1.7	0.81	s, p
Cystathionine	Cysta	Thioether	439258	0.07-0.55	0.02	2.3	2.9	0.63	s, p
Sarcosine*	Sarc	Methylated amino acid	1088	0.7-2.3	0.035	1.3	1.6	0.68	s, p
Histidine	His	Essential amino acid	6274	40-150	1	2	3	0.44^a	s, p
Tryptophan	Trp	Essential aromatic amino acid	6305	40-90	0.1	1.6	2.6	0.51	s, p
Kynurenine	Kyn	Trp metabolite	161166	1.0-3.3	0.12	1.9	2.3	0.68	s, p
Ornithine	Orn	Charged amino acid	6262	30-90	1	2.2	2.7	0.55^a	s, p
Aspartic acid	Asp	Charged amino acid	5960	0-26	0.5	1.8	4		s, p
Glutamic acid	Glu	Charged amino acid	33032	20-140	0.5	1.7	2.7		s, p
Lysine	Lys	Essential amino acid	5962	120-290	1.2	1.4	1.9	0.54^a	s, p
Alanine	Ala	Hydrophobic amino acid	5950	230-510	1	1.2	1.4	0.43^a	s, p
Phenylalanine	Phe	Essential aromatic amino acid	6140	26-85	0.5	1.5	3	0.44^a	s, p
Isoleucine	Ile	Essential BCAA**	6306	40-140	0.5	1.5	1.8	0.53^a	s, p
Leucine	Leu	Essential BCAA**	6106	70-170	0.5	3.4	4	0.52^a	s, p
Proline	Pro	Hydrophobic amino acid	145742	110-360	0.5	2.8	3.7	0.71^a	s, p
Valine	Val	Essential BCAA**	6287	150-350	0.5	2.2	2.7	0.38^a	s, p
Asparagine	Asn	Polar amino acid	6267	20-130	0.6	3	3	0.40^a	s, p
Glutamine	Gln	Polar amino acid	5961	390-700	10	2.1	2.7	0.42^a	s, p
Phenylacetylglutamine	PAGln	n-acyl-alpha amino acid	92258	2-100					s, p
Threonine	Thr	Essential amino acid	6288	70-240	1.2	2.4	3.3	0.44^a	s, p
Tyrosine	Tyr	Aromatic amino acid	6057	40-110	0.5	2.1	2.8	0.55^a	s, p
α-Hydroxyglutaric acid	aHG	α-Hydroxy acid	43	0.15-2	0.10	4.2	7.0		s, p
3-Hydroxyisobutyrate	3HIB	Val metabolite	440873	15-25	3	2.4	2.9		s, p
2-Hydroxybutyrate	aHB	α-Hydroxy acid	11266	10-60	3	1.7	2.3		s, p
3-Hydroxybutyrate	bHB	Ketone body	441	20-700	3	1.9	3.4		s, p
Acetoacetate	AcAc	Ketone body	96	10-200	5	5	5		s, p
Carboxymethyllysine	CML	an AGE***	123800	0.05-0.3	0.03	4.3	4.5		s, p
Carboxyethyllysine	CEL	an AGE***	23400779	0.05-0.4	0.03	4.1	4.4		s, p
2-Aminoadipic acid	2AAA	Lys metabolite	469	0.3-2.0	0.2	4.8	6.9		s, p
β-Aminoisobutyrate	BAIBA	Val metabolite	64956	0.3-2.0	0.2	2.5	3.7		s, p
β-Alanine	bAla	β-Amino acid	239	0.5-10	0.3	3	4.3		s, p
Citrate	Cit	Tricarboxylic acid	311	90-200	4	3	3.1		s, p
Isocitrate	iCit	Tricarboxylic acid	1198	2-22	0.3	2.8	3		s, p, csf
α-Ketoglutarate	aKG	Keto acid	51	2-40	0.5	3.7	3.7		s, p, csf
Fumarate	Fum	Dicarboxylic acid	444972	0.5-4	0.2	1.7	5.2		s, p, csf
Malate	Mal	β-Hydroxy acid	525	2-21	0.4	2.6	2.6		s, p, csf
Pyruvate	Pyr	α-Keto acid	1060	80-160	5	6	6.5		s, p, csf
Lactate	Lac	α-Hydroxy acid	612	500-1600	10	4.6	4.8		s, p, csf

*Sarcosine cannot be measured in EDTA-tubes from some suppliers because of the presence of sarcosine in these tubes; **BCAA, Branched chain amino acid; ***AGE, Advanced glycation end product.
^aXiaofei Yin, Orla Prendiville, Aoife E. McNamara, and Lorraine Brennan. Targeted Metabolomic Approach to Assess the Reproducibility of
Plasma Metabolites over a Four Month Period in a Free-Living Population. J. Proteome Res. 2022, 21, 683−690.

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.
LC-MS/MS: 35 µL vol.

All concentrations are reported in µmol/L.


Choline	Chol	Quarternary ammonium	305	5–15	0.5	2.8	3.2	0.36	s, p, u
Trimethylamine N-oxide	TMAO	Amine oxide	1145	0.5–60	0.1	4	4.1	<0.38	s, p, u
Betaine	Bet	Methylated amino acid	247	15–60	0.5	3.8	4.5	0.65	s, p, u
Dimethylglycine	DMG	Methylated amino acid	673	1.5–5	0.25	5.5	5.9	0.64	s, p, u
Total homocysteine	tHcy	Amino acid	91552	<15	0.1	1	2	0.72	s, p, u
Creatine	Crn	α-Amino acid	586	10–100	1	3.9	4		s, p, u
Creatinine	Creat	α-Amino acid	588	50–100	0.25	2.6	3.1	0.79	s, p, u
Methionine	Met	Essential amino acid	6137	18–50	1	4.1	4.5	0.33	s, p
Methionine sulfoxide	MetSo	Polar amino acid	158980	0.5–5	0.06	7.1	7.9	0.36	s, p
Total cysteine	tCys	Sulfur amino acid	5862	150–400	0.1	2	6	0.56	s, p
Histidine	His	Essential amino acid	6274	40–200	0.25	3.5	3.8		s, p
3-Methylhistidine	3-MH	Amino acid	92105	2.7–10	0.6	4.4	4.9		s, p, u
1-Methylhistidine	1-MH	Amino acid	64969	0.5–15	0.25	3.7	3.9		s, p, u
Citrulline	Ctn	Amino acid	9750	10–60	4	7-8	6-9		s, p
Arginine	Arg	Charged amino acid	6322	10–100	0.25	2.6	3	0.53	s, p
Asymmetric dimethylarginine	ADMA	Guanidinated amino acid	123831	0.4–1	0.08	5.2	5.5	0.53	s, p
Symmetric dimethylarginine	SDMA	Guanidinated amino acid	169148	0.3–0.9	0.08	4.8	5.2	0.62	s, p
Homoarginine	hArg	Guanidinated amino acid	9085	1–6	0.1	5.8	6	0.65	s, p
Trimethyllysine	TML	Methylated amino acid	440121	0.3–2	0.2	4	4.4	0.15	s, p
Butyrobetaine	BB	Quarternary ammonium	725	0.4–2	0.2				s, p
Carnitine	C0	Carnitine	288	20–80	0.5			0.69^a	s, p
Carnitine, total**	tC0	Carnitines		30–90	0.5				s, p
Acetylcarnitine	C2	Acylcarnitine	7045767	3–15	0.1			0.63	s, p
Propionylcarnitine	C3	Acylcarnitine	107738	0.2–.5	0.05			0.62	s, p
Butyrylcarnitine	C4	Acylcarnitine	213144	0.1–0.5	0.012				s, p
Isovalerylcarnitine	iC5	Acylcarnitine	6426851	0.06–0.2	0.05			0.68	s, p
Glutarylcarnitine	C5DC	Acylcarnitine	71464488	<0.05	0.01				s, p
Hexanoylcarnitine	C6	Acylcarnitine	6426853	0.01–1.2	0.01				s, p
Octanoylcarnitine	C8	Acylcarnitine	123701	0.06–0.3	0.05			0.41	s, p
Decanoylcarnitine	C10	Acylcarnitine	10245190	0.2–1	0.02				s, p
Dodecanoylcarnitine	C12	Acylcarnitine	168381	<0.4	0.02				s, p

*Measured in a separate assay after sample treatment with phospholipase D that does not affect the other metabolites of platform C, which are obtainable; **Measured in a separate assay involving alkaline hydrolysis of acylcarnitines.
^aFloegel A, Drogan D, Wang-Sattler R, Prehn C, Illig T, et al. (2011) Reliability of Serum Metabolite Concentrations over a 4-Month Period Using a
Targeted Metabolomic Approach. PLoS ONE 6(6): e21103. doi:10.1371/journal.pone.0021103

Kynurenine pathway and B vitamins (B1, B2, B3, B6).
LC-MS/MS: 60 µL vol.


3-Hydroxyanthranilic acid	HAA	Trp metabolite	86	10–80/0–7 nmol/L	2	4.6	6	0.54	s, p, csf
3-Hydroxykynurenine	HK	Trp metabolite	11811	25–80/0.1–25 nmol/L	2	3.2	4.5	0.62	s, p, csf
3-Indoxyl sulfate	3IS	Indole, Trp metabolite	10258	0.9–30 µmol/L	0.2				s, p, csf
4-Pyridoxic acid	PA	B6 vitamer	6723	10–200/0–15 nmol/L	0.5	3.6	5.8	0.58	s, p, csf
Anthranilic acid	AA	Trp metabolite	227	7–30/3–14 nmol/L	2	7.4	9.5	0.64	s, p, csf
Cotinine	Cot	Nicotine metabolite	854019	Non-smokers < ~5 nmol/L; passive smokers 5 – 85 nmol/L; smokers > 85nmol/L; heavy smokers (>25 cigarettes/day) > 1700 nmol/L	1	3	4.2	0.92	s, p,csf
Cystathionine	Cysta	Thioether	439258	70–550 nmol/L	0.02	3.4	4.5	0.63	s, p, csf
Flavin mononucleotide	FMN	B2 vitamer	643976	3–30/1–2 nmol/L	0.4	5.7	8.1	0.69	s, p, csf
Imidazole propionate	ImP	Histidine metabolite	70630	3–500 nmol/L	2				s, p
Indole-3-acetamide	IAM	Indole, Trp metabolite	397	0–10 nmol/L	1				s, p
Indole-3-acetate	IAA	Indole, Trp metabolite	802	0.3–23 µmol/L	0.05				s, p
Indole-3-aldehyde	IAld	Indole, Trp metabolite	10256	10–200 nmol/L	4				s, p
Indole-3-lactate	ILA	Indole, Trp metabolite	92904	0.08–5 µmol/L	0.025				s, p
Indole-3-propionate	IPA	Indole, Trp metabolite	3744	0.5–12 µmol/L	0.04				s, p
Kynurenic acid	KA	Trp metabolite	3845	20–100/0.5–15 nmol/L	0.4	4.4	5.4	0.68	s, p, csf
Kynurenine	Kyn	Trp metabolite	161166	1.0–3.3/0.02–0.12 µmol/L	0.007	3.6	5.1	0.68	s, p, csf
N1-methylnicotinamide	mNAM	B3 vitamer	457	20–250/5–100 nmol/L	5	4	5.5		s, p, csf
Neopterin	Neopt	Pteridine	4455	5–50/5–50 nmol/L	0.7	5.3	6.6	0.6	s, p, csf
Nicotinamide	NAM	B3 vitamer	936	100–600/5–200 nmol/L	20	4.2	6.1		s, p, csf
Nicotinic acid	NA	B3 vitamer	938	<20 nmol/L	10	4	5.4		s, p, csf
Picolinic acid	Pic	Trp metabolite	1018	20–100/5–100 nmol/L	8	6-7	5-8		s, p, csf
Pyridoxal	PL	B6 vitamer	1050	5–150/10–50 nmol/L	0.2	3.5	5.1	0.62	s, p, csf
Pyridoxal 5-phosphate	PLP	B6 vitamer	1051	15–150/7–70 nmol//L	0.2	3.5	5.7	0.7	s, p, csf
Pyridoxine	PN	B6 vitamer	1054	Exogenous metabolite, reflecting B vitamin supplement use	0.5	4.5	5.2		s, p
Quinaldic acid	Qld	Trp (KA) metabolite	7124	0.2–100/0.1–10 nmol/L	0.5	6-7	6-8		s, p
Quinolinic acid	QA	Trp metabolite	1066	150–700/10–150 nmol/L	1.6	7-8	7-10		s, p, csf
Riboflavin	Ribo	B2 vitamer	493570	5–100/5–25 nmol/L	0.2	6	7.1	0.79	s, p, csf
Thiamine	Thi	B1 vitamer	1130	2–50/5–40 nmol/L	0.5	3.5	4.9		s, p, csf
Thiamine monophosphate	TMP	B1 vitamer	1131	2–15/25–75 nmol/L	0.5	7.1	11.6		s, p, csf
Trans-3-hydroxycotinine	OHCot	Nicotine metabolite	107963	Concentrations relative to cotinine, with OHCot/cotininine ratio ranging from 0.02-0.90	2	3.6	4.5	0.85	s, p, csf
Trigonelline	Trig	Alkaloid	5570	0.4–25 µmol/L	0.01	2.9	3.8	0.66	s, p, csf
Trimethylamine N-oxide	TMAO	Amine oxide	1145	0.5–60/0.2–12 µmol/L	0.1	4.2	6.9	<0.38	s, p, csf
Tryptophan	Trp	Essential aromatic amino acid	6305	40–90/2–7 µmol/L	4	3.1	3.9	0.51	s, p, csf
Xanthurenic acid	XA	Trp metabolite	5699	2–35/<0.5 nmol/L	0.5	4.8	5.7	0.58	s, p, csf

Folate species and catabolites.
LC-MS/MS: 60 µL vol.

All concentrations are reported in nmol/L.


5-Methyl-tetrahydrofolate	mTHF	Folate	439234	>7.5	0.07	5-9	4-5	s, p
5-Formyl-tetrahydrofolate	fTHF	Folate	6006	0-2	0.52	8-9	6-11	s, p
Folic acid	FA	Folate	6037	0-2	0.27	7-8	6-12	s, p
Serum folate as pABG equivalents	S pABG	Folate		>7.5				s, p
RBC folate as pABG equivalents	E pABG	Folate		>340				e
Para-aminobenzoylglutamate	pABG	Folate catabolite	196473	0-0.5	0.08	6-9	3-10	s, p
Acetamidobenzoylglutamate	apABG	Folate catabolite	3080868	0.1-1	0.13	5-6	5-9	s, p
4-α-hydroxy-5-methyl-THF	hmTHF	Oxidized folate			0.2	6-10	6-7	s, p

Folate (B9) and cobalamin (B12).
Microbiological assay: 15-35 µL vol.


Serum folate	s-Folate	B vitamin	>7.5 nmol/L	2	4	5	0.56	s, p
Erythrocyte folate	e-Folate	B vitamin	>340 nmol/L					e
Serum cobalamin	s-B12	B vitamin	>150 pmol/L	30	4	5	0.82	s, p

Protein biomarkers and variants.
MALDI-TOF MS: 30 µL vol.


C-reactive protein	CRP	Protein	P02741	1	0-10 µg/mL***	0.1	4-5	7-9	0.5-0.7	s, p
Serum amyloid A	SAA	Protein	P0DJI8, P0DJI9	18	0-20 µg/mL	0.05	4-5	8-10	0.4-0.7	s, p
Calprotectin	S100A	Protein	P05109, P06702	6*	0-30 µg/mL	0.02	4-7	7-8	0.3-0.5	s, p, csf
Cystatin C	CnC	Protein	P01034	5*	0-8 µg/mL	0.01	4-5	4-5	0.7	s, p, csf
Glycated hemoglobin	HbA1c	Protein	P69905, F8W6P5		4-14 %		2-6			w

*Mass interference of S100A and CnC proteoforms; **ICCs of proteoforms are reported here; *** high sensitive CRP (hs-CRP)

Lipid-soluble vitamins and long-chain acylcarnitines.
LC-MS/MS: 50-100 µL vol.


All-trans retinol	Vit. A	A vitamer	445354	0.3-8 µmol/L	0.1	2.9	3.6	0.87	s, p
25-hydroxy vitamin D2	25OH-D2	D vitamer	5710148	0-60 nmol/L	5	6.6	8.1		s, p
25-hydroxy vitamin D3	25OH-D3	D vitamer	5283731	10-280 nmol/L	3.3	5.1	6.1	0.71	s, p
α-tocopherol	aToc	E vitamer	14985	11-106 µmol/L	2	4.3	5.8	0.86	s, p
γ-tocopherol	gToc	E vitamer	92729	0.5-11 µmol/L	0.1	3.7	5		s, p
Phylloquinone	Vit. K1	K vitamer	5284607	0.5-20 nmol/L	0.5	4.8	7.4	0.49	s, p
Myristoylcarnitine	C14	Acylcarnitine	6426854	10-216 nmol/L				0.38^a	s, p
Palmitoylcarnitine	C16	Acylcarnitine	461	40-310 nmol/L				0.49^a	s, p
Stearoylcarnitine	C18	Acylcarnitine	52922056	17-100 nmol/L				0.40^a	s, p
Oleoylcarnitine	C18:1	Acylcarnitine	46907933	40-412 nmol/L				0.66^b	s, p
Linoleylcarnitine	C18:2	Acylcarnitine	6450015	10-297 nmol/L					s, p

^aFloegel A, Drogan D, Wang-Sattler R, Prehn C, Illig T, et al. (2011) Reliability of Serum Metabolite Concentrations over a 4-Month Period Using a
Targeted Metabolomic Approach. PLoS ONE 6(6): e21103. doi:10.1371/journal.pone.0021103
^bXiaofei Yin, Orla Prendiville, Aoife E. McNamara, and Lorraine Brennan. Targeted Metabolomic Approach to Assess the Reproducibility of
Plasma Metabolites over a Four Month Period in a Free-Living Population. J. Proteome Res. 2022, 21, 683−690.

Short-, medium- and long-chain acylcarnitines.
LC (HILIC)-MS/MS. This platform is under development.

All concentrations are reported in µmol/L.


Butyrobetaine	BB	Quarternary ammonium	725	0.4-2	0.2		s, p
Carnitine	C0	Carnitine	288	20-80	0.5	0.76^b	s, p
Acetylcarnitine	C2	Acylcarnitine	7045767	3-15	0.1	0.63	s, p
Propionylcarnitine	C3	Acylcarnitine	107738	0.2-1.5	0.05	0.62	s, p
Butyrylcarnitine	C4	Acylcarnitine	213144	0.1-0.5	0.012	0.79^b	s, p
Isovalerylcarnitine	iC5	Acylcarnitine	6426851	0.06-0.2	0.05	0.68	s, p
Hexanoylcarnitine	C6	Acylcarnitine	6426853	0.01-1.2	0.01		s, p
Octanoylcarnitine	C8	Acylcarnitine	123701	0.06-0.3	0.05	0.41	s, p
Decanoylcarnitine	C10	Acylcarnitine	10245190	0.2-1	0.02	0.67^b	s, p
Dodecanoylcarnitine	C12	Acylcarnitine	168381	< 0.4	0.02		s, p
Myristoylcarnitine	C14	Acylcarnitine	6426854	0.01-0.1		0.38^a	s, p
Palmitoylcarnitine	C16	Acylcarnitine	461	0.05-0.25		0.49^a	s, p
Stearoylcarnitine	C18	Acylcarnitine	52922056	0.03-0.1		0.40^a	s, p
Oleoylcarnitine	C18:1	Acylcarnitine	46907933	0.04-0.2			s, p
Linoleylcarnitine	C18:2	Acylcarnitine	6450015	0.01-0.1			s, p

Short-chain fatty acids.
Volume: 50 µL

All concentrations are reported as µmol/L; CVs (%) shown as within-day (Wtn-day) and between-day (Btw-day) variations; sample matrices: serum (s), plasma (p), cerebrospinal fluid (csf).


Acetate	Ace	Short-chain fatty acid	175-176	5-300	s, p
Butyrate	But	Short-chain fatty acid	264	1-30	s, p
Formate	Frm	Short-chain fatty acid	284	8-100	s, p, csf
Isobutyrate	iBut	Short-chain fatty acid	6590	0.7-6	s, p, csf
Isovalerate	iVlr	Short-chain fatty acid	10430	0.3-3	s, p
Propionate	Pro	Short-chain fatty acid	1042	1-13	s, p
Valerate	Vlr	Short-chain fatty acid	7991	0.2-1	s, p
α-Methylbutyrate	aMB	Short-chain fatty acid	8314	0.3-3	s, p

Amino- and carboxylic acids. TCA metabolites and intermediates. Volume: 50 µL

All concentrations are reported as µmol/L; CVs (%) shown as within-day (Wtn-day) and between-day (Btw-day) variations; sample matrices: serum (s), plasma (p), urine (u).


Methylmalonic acid	MMA	Carboxylic acid	487	<0.26	0.03	2.4	3	0.81	s, p
Total homocysteine	tHcy	Sulfur amino acid	91552	5-15	0.1	1.4	2.7	0.72	s, p
Total cysteine	tCys	Sulfur amino acid	5862	150-350	50	1	2	0.62	s, p
Methionine	Met	Essential amino acid	6137	18-50	1	2.2	4.1	0.33	s, p
Serine	Ser	Polar amino acid	5951	95-200	5	1.3	1.7	0.71	s, p
Glycine	Gly	Hydrophobic amino acid	750	150-350	3	1.3	1.7	0.81	s, p
Cystathionine	Cysta	Thioether	439258	0.07-0.55	0.02	2.3	2.9	0.63	s, p
Sarcosine*	Sarc	Methylated amino acid	1088	0.7-2.3	0.035	1.3	1.6	0.68	s, p
Histidine	His	Essential amino acid	6274	40-150	1	2	3	0.44^a	s, p
Tryptophan	Trp	Essential aromatic amino acid	6305	40-90	0.1	1.6	2.6	0.51	s, p
Kynurenine	Kyn	Trp metabolite	161166	1.0-3.3	0.12	1.9	2.3	0.68	s, p
Ornithine	Orn	Charged amino acid	6262	30-90	1	2.2	2.7	0.55^a	s, p
Aspartic acid	Asp	Charged amino acid	5960	0-26	0.5	1.8	4		s, p
Glutamic acid	Glu	Charged amino acid	33032	20-140	0.5	1.7	2.7		s, p
Lysine	Lys	Essential amino acid	5962	120-290	1.2	1.4	1.9	0.54^a	s, p
Alanine	Ala	Hydrophobic amino acid	5950	230-510	1	1.2	1.4	0.43^a	s, p
Phenylalanine	Phe	Essential aromatic amino acid	6140	26-85	0.5	1.5	3	0.44^a	s, p
Isoleucine	Ile	Essential BCAA**	6306	40-140	0.5	1.5	1.8	0.53^a	s, p
Leucine	Leu	Essential BCAA**	6106	70-170	0.5	3.4	4	0.52^a	s, p
Proline	Pro	Hydrophobic amino acid	145742	110-360	0.5	2.8	3.7	0.71^a	s, p
Valine	Val	Essential BCAA**	6287	150-350	0.5	2.2	2.7	0.38^a	s, p
Asparagine	Asn	Polar amino acid	6267	20-130	0.6	3	3	0.40^a	s, p
Glutamine	Gln	Polar amino acid	5961	390-700	10	2.1	2.7	0.42^a	s, p
Phenylacetylglutamine	PAGln	n-acyl-alpha amino acid	92258	2-100					s, p
Threonine	Thr	Essential amino acid	6288	70-240	1.2	2.4	3.3	0.44^a	s, p
Tyrosine	Tyr	Aromatic amino acid	6057	40-110	0.5	2.1	2.8	0.55^a	s, p
α-Hydroxyglutaric acid	aHG	α-Hydroxy acid	43	0.15-2	0.10	4.2	7.0		s, p
3-Hydroxyisobutyrate	3HIB	Val metabolite	440873	15-25	3	2.4	2.9		s, p
2-Hydroxybutyrate	aHB	α-Hydroxy acid	11266	10-60	3	1.7	2.3		s, p
3-Hydroxybutyrate	bHB	Ketone body	441	20-700	3	1.9	3.4		s, p
Acetoacetate	AcAc	Ketone body	96	10-200	5	5	5		s, p
Carboxymethyllysine	CML	an AGE***	123800	0.05-0.3	0.03	4.3	4.5		s, p
Carboxyethyllysine	CEL	an AGE***	23400779	0.05-0.4	0.03	4.1	4.4		s, p
2-Aminoadipic acid	2AAA	Lys metabolite	469	0.3-2.0	0.2	4.8	6.9		s, p
β-Aminoisobutyrate	BAIBA	Val metabolite	64956	0.3-2.0	0.2	2.5	3.7		s, p
β-Alanine	bAla	β-Amino acid	239	0.5-10	0.3	3	4.3		s, p
Citrate	Cit	Tricarboxylic acid	311	90-200	4	3	3.1		s, p
Isocitrate	iCit	Tricarboxylic acid	1198	2-22	0.3	2.8	3		s, p, csf
α-Ketoglutarate	aKG	Keto acid	51	2-40	0.5	3.7	3.7		s, p, csf
Fumarate	Fum	Dicarboxylic acid	444972	0.5-4	0.2	1.7	5.2		s, p, csf
Malate	Mal	β-Hydroxy acid	525	2-21	0.4	2.6	2.6		s, p, csf
Pyruvate	Pyr	α-Keto acid	1060	80-160	5	6	6.5		s, p, csf
Lactate	Lac	α-Hydroxy acid	612	500-1600	10	4.6	4.8		s, p, csf

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.
Volume: 35 µL

All concentrations are reported as µmol/L; CVs (%) shown as within-day (Wtn-day) and between-day (Btw-day) variations; sample matrices: serum (s), plasma (p), urine (u).


Choline	Chol	Quarternary ammonium	305	5–15	0.5	2.8	3.2	0.36	s, p, u
Trimethylamine N-oxide	TMAO	Amine oxide	1145	0.5–60	0.1	4	4.1	<0.38	s, p, u
Betaine	Bet	Methylated amino acid	247	15–60	0.5	3.8	4.5	0.65	s, p, u
Dimethylglycine	DMG	Methylated amino acid	673	1.5–5	0.25	5.5	5.9	0.64	s, p, u
Total homocysteine	tHcy	Amino acid	91552	<15	0.1	1	2	0.72	s, p, u
Creatine	Crn	α-Amino acid	586	10–100	1	3.9	4		s, p, u
Creatinine	Creat	α-Amino acid	588	50–100	0.25	2.6	3.1	0.79	s, p, u
Methionine	Met	Essential amino acid	6137	18–50	1	4.1	4.5	0.33	s, p
Methionine sulfoxide	MetSo	Polar amino acid	158980	0.5–5	0.06	7.1	7.9	0.36	s, p
Total cysteine	tCys	Sulfur amino acid	5862	150–400	0.1	2	6	0.56	s, p
Histidine	His	Essential amino acid	6274	40–200	0.25	3.5	3.8		s, p
3-Methylhistidine	3-MH	Amino acid	92105	2.7–10	0.6	4.4	4.9		s, p, u
1-Methylhistidine	1-MH	Amino acid	64969	0.5–15	0.25	3.7	3.9		s, p, u
Citrulline	Ctn	Amino acid	9750	10–60	4	7-8	6-9		s, p
Arginine	Arg	Charged amino acid	6322	10–100	0.25	2.6	3	0.53	s, p
Asymmetric dimethylarginine	ADMA	Guanidinated amino acid	123831	0.4–1	0.08	5.2	5.5	0.53	s, p
Symmetric dimethylarginine	SDMA	Guanidinated amino acid	169148	0.3–0.9	0.08	4.8	5.2	0.62	s, p
Homoarginine	hArg	Guanidinated amino acid	9085	1–6	0.1	5.8	6	0.65	s, p
Trimethyllysine	TML	Methylated amino acid	440121	0.3–2	0.2	4	4.4	0.15	s, p
Butyrobetaine	BB	Quarternary ammonium	725	0.4–2	0.2				s, p
Carnitine	C0	Carnitine	288	20–80	0.5			0.69^a	s, p
Carnitine, total**	tC0	Carnitines		30–90	0.5				s, p
Acetylcarnitine	C2	Acylcarnitine	7045767	3–15	0.1			0.63	s, p
Propionylcarnitine	C3	Acylcarnitine	107738	0.2–.5	0.05			0.62	s, p
Butyrylcarnitine	C4	Acylcarnitine	213144	0.1–0.5	0.012				s, p
Isovalerylcarnitine	iC5	Acylcarnitine	6426851	0.06–0.2	0.05			0.68	s, p
Glutarylcarnitine	C5DC	Acylcarnitine	71464488	<0.05	0.01				s, p
Hexanoylcarnitine	C6	Acylcarnitine	6426853	0.01–1.2	0.01				s, p
Octanoylcarnitine	C8	Acylcarnitine	123701	0.06–0.3	0.05			0.41	s, p
Decanoylcarnitine	C10	Acylcarnitine	10245190	0.2–1	0.02				s, p
Dodecanoylcarnitine	C12	Acylcarnitine	168381	<0.4	0.02				s, p

Kynurenine pathway and B vitamins (B1, B2, B3, B6).
Volume: 60 µL

All concentrations are reported as µmol/L or nmol/L. CVs (%) shown as within-day (Wtn-day) and between-day (Btw-day) variations; sample matrices: serum (s), plasma (p), urine (u), cerebrospinal fluid (csf).


3-Hydroxyanthranilic acid	HAA	Trp metabolite	86	10–80/0–7 nmol/L	2	4.6	6	0.54	s, p, csf
3-Hydroxykynurenine	HK	Trp metabolite	11811	25–80/0.1–25 nmol/L	2	3.2	4.5	0.62	s, p, csf
3-Indoxyl sulfate	3IS	Indole, Trp metabolite	10258	0.9–30 µmol/L	0.2				s, p, csf
4-Pyridoxic acid	PA	B6 vitamer	6723	10–200/0–15 nmol/L	0.5	3.6	5.8	0.58	s, p, csf
Anthranilic acid	AA	Trp metabolite	227	7–30/3–14 nmol/L	2	7.4	9.5	0.64	s, p, csf
Cotinine	Cot	Nicotine metabolite	854019	Non-smokers < ~5 nmol/L; passive smokers 5 – 85 nmol/L; smokers > 85nmol/L; heavy smokers (>25 cigarettes/day) > 1700 nmol/L	1	3	4.2	0.92	s, p,csf
Cystathionine	Cysta	Thioether	439258	70–550 nmol/L	0.02	3.4	4.5	0.63	s, p, csf
Flavin mononucleotide	FMN	B2 vitamer	643976	3–30/1–2 nmol/L	0.4	5.7	8.1	0.69	s, p, csf
Imidazole propionate	ImP	Histidine metabolite	70630	3–500 nmol/L	2				s, p
Indole-3-acetamide	IAM	Indole, Trp metabolite	397	0–10 nmol/L	1				s, p
Indole-3-acetate	IAA	Indole, Trp metabolite	802	0.3–23 µmol/L	0.05				s, p
Indole-3-aldehyde	IAld	Indole, Trp metabolite	10256	10–200 nmol/L	4				s, p
Indole-3-lactate	ILA	Indole, Trp metabolite	92904	0.08–5 µmol/L	0.025				s, p
Indole-3-propionate	IPA	Indole, Trp metabolite	3744	0.5–12 µmol/L	0.04				s, p
Kynurenic acid	KA	Trp metabolite	3845	20–100/0.5–15 nmol/L	0.4	4.4	5.4	0.68	s, p, csf
Kynurenine	Kyn	Trp metabolite	161166	1.0–3.3/0.02–0.12 µmol/L	0.007	3.6	5.1	0.68	s, p, csf
N1-methylnicotinamide	mNAM	B3 vitamer	457	20–250/5–100 nmol/L	5	4	5.5		s, p, csf
Neopterin	Neopt	Pteridine	4455	5–50/5–50 nmol/L	0.7	5.3	6.6	0.6	s, p, csf
Nicotinamide	NAM	B3 vitamer	936	100–600/5–200 nmol/L	20	4.2	6.1		s, p, csf
Nicotinic acid	NA	B3 vitamer	938	<20 nmol/L	10	4	5.4		s, p, csf
Picolinic acid	Pic	Trp metabolite	1018	20–100/5–100 nmol/L	8	6-7	5-8		s, p, csf
Pyridoxal	PL	B6 vitamer	1050	5–150/10–50 nmol/L	0.2	3.5	5.1	0.62	s, p, csf
Pyridoxal 5-phosphate	PLP	B6 vitamer	1051	15–150/7–70 nmol//L	0.2	3.5	5.7	0.7	s, p, csf
Pyridoxine	PN	B6 vitamer	1054	Exogenous metabolite, reflecting B vitamin supplement use	0.5	4.5	5.2		s, p
Quinaldic acid	Qld	Trp (KA) metabolite	7124	0.2–100/0.1–10 nmol/L	0.5	6-7	6-8		s, p
Quinolinic acid	QA	Trp metabolite	1066	150–700/10–150 nmol/L	1.6	7-8	7-10		s, p, csf
Riboflavin	Ribo	B2 vitamer	493570	5–100/5–25 nmol/L	0.2	6	7.1	0.79	s, p, csf
Thiamine	Thi	B1 vitamer	1130	2–50/5–40 nmol/L	0.5	3.5	4.9		s, p, csf
Thiamine monophosphate	TMP	B1 vitamer	1131	2–15/25–75 nmol/L	0.5	7.1	11.6		s, p, csf
Trans-3-hydroxycotinine	OHCot	Nicotine metabolite	107963	Concentrations relative to cotinine, with OHCot/cotininine ratio ranging from 0.02-0.90	2	3.6	4.5	0.85	s, p, csf
Trigonelline	Trig	Alkaloid	5570	0.4–25 µmol/L	0.01	2.9	3.8	0.66	s, p, csf
Trimethylamine N-oxide	TMAO	Amine oxide	1145	0.5–60/0.2–12 µmol/L	0.1	4.2	6.9	<0.38	s, p, csf
Tryptophan	Trp	Essential aromatic amino acid	6305	40–90/2–7 µmol/L	4	3.1	3.9	0.51	s, p, csf
Xanthurenic acid	XA	Trp metabolite	5699	2–35/<0.5 nmol/L	0.5	4.8	5.7	0.58	s, p, csf

Folate species and catabolites.
LC-MS/MS: 60 µL vol.

All concentrations are reported as nmol/L. CVs (%) shown as within-day (Wtn-day) and between-day (Btw-day) variations; sample matrices: serum (s), plasma (p).


5-Methyl-tetrahydrofolate	mTHF	Folate	439234	>7.5	0.07	5-9	4-5	s, p
5-Formyl-tetrahydrofolate	fTHF	Folate	6006	0-2	0.52	8-9	6-11	s, p
Folic acid	FA	Folate	6037	0-2	0.27	7-8	6-12	s, p
Serum folate as pABG equivalents	S pABG	Folate		>7.5				s, p
RBC folate as pABG equivalents	E pABG	Folate		>340				e
Para-aminobenzoylglutamate	pABG	Folate catabolite	196473	0-0.5	0.08	6-9	3-10	s, p
Acetamidobenzoylglutamate	apABG	Folate catabolite	3080868	0.1-1	0.13	5-6	5-9	s, p
4-α-hydroxy-5-methyl-THF	hmTHF	Oxidized folate			0.2	6-10	6-7	s, p

Folate (B9) and cobalamin (B12).
Microbiological assay: 15-35 µL vol.

All concentrations are reported as nmol/L or pmol/L.


Serum folate	s-Folate	B vitamin	>7.5 nmol/L	2	4	5	0.56	s, p
Erythrocyte folate	e-Folate	B vitamin	>340 nmol/L					e
Serum cobalamin	s-B12	B vitamin	>150 pmol/L	30	4	5	0.82	s, p

Protein biomarkers and variants.
MALDI-TOF MS: 30 µL vol.

All concentrations are reported as µmol/L or %.


C-reactive protein	CRP	Protein	P02741	1	0-10 µg/mL***	0.1	4-5	7-9	0.5-0.7	s, p
Serum amyloid A	SAA	Protein	P0DJI8, P0DJI9	18	0-20 µg/mL	0.05	4-5	8-10	0.4-0.7	s, p
Calprotectin	S100A	Protein	P05109, P06702	6*	0-30 µg/mL	0.02	4-7	7-8	0.3-0.5	s, p, csf
Cystatin C	CnC	Protein	P01034	5*	0-8 µg/mL	0.01	4-5	4-5	0.7	s, p, csf
Glycated hemoglobin	HbA1c	Protein	P69905, F8W6P5		4-14 %		2-6			w

*Mass interference of S100A and CnC proteoforms; **ICCs of proteoforms can be found here.

Lipid-soluble vitamins and long-chain acylcarnitines.
LC-MS/MS: 50-100 µL vol.

All concentrations are reported as µmol/L or nmol/L.


All-trans retinol	Vit. A	A vitamer	445354	0.3-8 µmol/L	0.1	2.9	3.6	0.87	s, p
25-hydroxy vitamin D2	25OH-D2	D vitamer	5710148	0-60 nmol/L	5	6.6	8.1		s, p
25-hydroxy vitamin D3	25OH-D3	D vitamer	5283731	10-280 nmol/L	3.3	5.1	6.1	0.71	s, p
α-tocopherol	aToc	E vitamer	14985	11-106 µmol/L	2	4.3	5.8	0.86	s, p
γ-tocopherol	gToc	E vitamer	92729	0.5-11 µmol/L	0.1	3.7	5		s, p
Phylloquinone	Vit. K1	K vitamer	5284607	0.5-20 nmol/L	0.5	4.8	7.4	0.49	s, p
Myristoylcarnitine	C14	Acylcarnitine	6426854	10-216 nmol/L				0.38^a	s, p
Palmitoylcarnitine	C16	Acylcarnitine	461	40-310 nmol/L				0.49^a	s, p
Stearoylcarnitine	C18	Acylcarnitine	52922056	17-100 nmol/L				0.40^a	s, p
Oleoylcarnitine	C18:1	Acylcarnitine	46907933	40-412 nmol/L				0.66^b	s, p
Linoleylcarnitine	C18:2	Acylcarnitine	6450015	10-297 nmol/L					s, p

This platform is under development.
Short-, medium- and long-chain acylcarnitines.
LC (HILIC)-MS/MS.

All concentrations are reported as µmol/L.


Butyrobetaine	BB	Quarternary ammonium	725	0.4-2	0.2		s, p
Carnitine	C0	Carnitine	288	20-80	0.5	0.76^b	s, p
Acetylcarnitine	C2	Acylcarnitine	7045767	3-15	0.1	0.63	s, p
Propionylcarnitine	C3	Acylcarnitine	107738	0.2-1.5	0.05	0.62	s, p
Butyrylcarnitine	C4	Acylcarnitine	213144	0.1-0.5	0.012	0.79^b	s, p
Isovalerylcarnitine	iC5	Acylcarnitine	6426851	0.06-0.2	0.05	0.68	s, p
Hexanoylcarnitine	C6	Acylcarnitine	6426853	0.01-1.2	0.01		s, p
Octanoylcarnitine	C8	Acylcarnitine	123701	0.06-0.3	0.05	0.41	s, p
Decanoylcarnitine	C10	Acylcarnitine	10245190	0.2-1	0.02	0.67^b	s, p
Dodecanoylcarnitine	C12	Acylcarnitine	168381	< 0.4	0.02		s, p
Myristoylcarnitine	C14	Acylcarnitine	6426854	0.01-0.1		0.38^a	s, p
Palmitoylcarnitine	C16	Acylcarnitine	461	0.05-0.25		0.49^a	s, p
Stearoylcarnitine	C18	Acylcarnitine	52922056	0.03-0.1		0.40^a	s, p
Oleoylcarnitine	C18:1	Acylcarnitine	46907933	0.04-0.2			s, p
Linoleylcarnitine	C18:2	Acylcarnitine	6450015	0.01-0.1			s, p

*Multianalyte determination is carried out in a single aliquot. Volume requirement is independent of the number of metabolites. Reported values are not strictly normal reference range, which depends on the population, and several factors, including age, gender, ethnicity and procedures for sample handling and analytical technology. Reported values are concentrations that we and others have observed or reported in various cohorts of healthy subjects. For some biomarkers the assay performance may be different from those given in published articles. This is due to continuous improvements of the methods. LODs, CVs, and ICCs are not available for all biomarkers.

April 28, 2023

High-Precision Metabolomics

Methods

Analytical platforms

Short-chain fatty acids.
GC-MS/MS: 50 µL vol.

Amino- and carboxylic acids. TCA metabolites and intermediates.
GC-MS/MS: 50 µL vol.

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.
LC-MS/MS: 35 µL vol.

Kynurenine pathway and B vitamins (B1, B2, B3, B6).
LC-MS/MS: 60 µL vol.

Folate species and catabolites.
LC-MS/MS: 60 µL vol.

Folate (B9) and cobalamin (B12).
Microbiological assay: 15-35 µL vol.

Protein biomarkers and variants.
MALDI-TOF MS: 30 µL vol.

Lipid-soluble vitamins and long-chain acylcarnitines.
LC-MS/MS: 50-100 µL vol.

Short-, medium- and long-chain acylcarnitines.
LC (HILIC)-MS/MS. This platform is under development.

Short-chain fatty acids.
Volume: 50 µL

Amino- and carboxylic acids. TCA metabolites and intermediates. Volume: 50 µL

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.
Volume: 35 µL

Kynurenine pathway and B vitamins (B1, B2, B3, B6).
Volume: 60 µL

Folate species and catabolites.
LC-MS/MS: 60 µL vol.

Folate (B9) and cobalamin (B12).
Microbiological assay: 15-35 µL vol.

Protein biomarkers and variants.
MALDI-TOF MS: 30 µL vol.

Lipid-soluble vitamins and long-chain acylcarnitines.
LC-MS/MS: 50-100 µL vol.

This platform is under development.
Short-, medium- and long-chain acylcarnitines.
LC (HILIC)-MS/MS.

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Legal Info

Contact

© 2023 BEVITAL AS – All Rights Reserved

Methods

Analytical platforms

Short-chain fatty acids.GC-MS/MS: 50 µL vol.

Amino- and carboxylic acids. TCA metabolites and intermediates.GC-MS/MS: 50 µL vol.

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.LC-MS/MS: 35 µL vol.

Kynurenine pathway and B vitamins (B1, B2, B3, B6).LC-MS/MS: 60 µL vol.

Folate species and catabolites.LC-MS/MS: 60 µL vol.

Folate (B9) and cobalamin (B12).Microbiological assay: 15-35 µL vol.

Protein biomarkers and variants.MALDI-TOF MS: 30 µL vol.

Lipid-soluble vitamins and long-chain acylcarnitines.LC-MS/MS: 50-100 µL vol.

Short-, medium- and long-chain acylcarnitines.LC (HILIC)-MS/MS. This platform is under development.

Short-chain fatty acids.Volume: 50 µL

Amino- and carboxylic acids. TCA metabolites and intermediates. Volume: 50 µL

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.Volume: 35 µL

Kynurenine pathway and B vitamins (B1, B2, B3, B6).Volume: 60 µL

Folate species and catabolites.LC-MS/MS: 60 µL vol.

Folate (B9) and cobalamin (B12).Microbiological assay: 15-35 µL vol.

Protein biomarkers and variants.MALDI-TOF MS: 30 µL vol.

Lipid-soluble vitamins and long-chain acylcarnitines.LC-MS/MS: 50-100 µL vol.

This platform is under development.Short-, medium- and long-chain acylcarnitines.LC (HILIC)-MS/MS.

Address

Legal Info

Contact

© 2023 BEVITAL AS – All Rights Reserved

Short-chain fatty acids.
GC-MS/MS: 50 µL vol.

Amino- and carboxylic acids. TCA metabolites and intermediates.
GC-MS/MS: 50 µL vol.

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.
LC-MS/MS: 35 µL vol.

Kynurenine pathway and B vitamins (B1, B2, B3, B6).
LC-MS/MS: 60 µL vol.

Folate species and catabolites.
LC-MS/MS: 60 µL vol.

Folate (B9) and cobalamin (B12).
Microbiological assay: 15-35 µL vol.

Protein biomarkers and variants.
MALDI-TOF MS: 30 µL vol.

Lipid-soluble vitamins and long-chain acylcarnitines.
LC-MS/MS: 50-100 µL vol.

Short-, medium- and long-chain acylcarnitines.
LC (HILIC)-MS/MS. This platform is under development.

Short-chain fatty acids.
Volume: 50 µL

Choline derivatives. Charged, methylated or sulfur amino acids. Short- and medium-chain acylcarnitines.
Volume: 35 µL

Kynurenine pathway and B vitamins (B1, B2, B3, B6).
Volume: 60 µL

Folate species and catabolites.
LC-MS/MS: 60 µL vol.

Folate (B9) and cobalamin (B12).
Microbiological assay: 15-35 µL vol.

Protein biomarkers and variants.
MALDI-TOF MS: 30 µL vol.

Lipid-soluble vitamins and long-chain acylcarnitines.
LC-MS/MS: 50-100 µL vol.

This platform is under development.
Short-, medium- and long-chain acylcarnitines.
LC (HILIC)-MS/MS.