Bile Acid Mixes
Bile acids (BAs) are steroid-like compounds that act as a detergent in the breakdown of fats. This family of compounds comprises primary BAs (synthesized in the liver) and secondary BAs (produced in the gut by bacteria following modification of the primary BAs). These are essential regulatory compounds that are involved in various metabolic processes (e.g., cholesterol and lipid metabolism) and signaling interactions (e.g., in glucose and energy homeostasis).
Toward research and development efforts in the microbiome field, CIL offers stable isotope-labeled (and unlabeled) BA mixes. These formulations are dried down, with unconjugated and glyco/tauro-conjugated BAs (with or without sulfated groups) in separate vials. The mixes can be used in untargeted and targeted LC-MS methods for a variety of purposes (from quality control to quantification).
Related Resources
➤ Stable Isotope Standards for Mass Spectrometry
➤ Stable Isotope-Labeled Products for Metabolic Research
➤ Stable Isotope-Labeled Products for Microbiome Research
➤ Stable Isotope-Labeled Mixtures, Sets, and Kits
➤ Mixtures, Sets, and Kits for MS ‘Omics and MS/MS Screening
Application Notes
➤ Bile Acid Analysis in Mouse Samples to Study Liver Cholestasis Etiology
➤ Rapid Analysis of 17 Bile Acids in Human Plasma by LC-MS/MS
Researcher Perspective
➤ Quantification of Bile Acids in Life Science-Based Research
Technical Note
➤ Quantitative Analysis and Structural Characterization of Bile Acids Using the ZenoTOF 7600 System
➤ Quantitative and Qualitative Bile Acid Analysis on the ZenoTOF 8600 System Using EAD
Metabolomics Bile Acid Mixes
Related Products
Filters:
Isotope Label
Isotopic Enrichment Range
Label Type
Molecular Weight Range
Product Form
Product Form 2
Bile Acid Types
Conjugated Bile Acids
❛❛The materials that Cambridge Isotope Laboratories (CIL) supply are always of the highest quality in terms of chemical and isotopic purity. Recently, we have embarked on two new major research areas involving the analyses of bile acids (BAs) and per- and polyfluorinated alkylsubstances (PFAS). The standards/mixes from CIL that enable these, and other, projects are precisely what we have come to expect – perfection!❜❜
– David C. Muddiman, PhD | Jacob and Betty Belin Distinguished Professor, Department of Chemistry, North Carolina State University
Director of Molecular Education, Technology, and Research Innovation Center (METRIC)
Frequently Asked Questions
What are the structures of the bile acids present in these mixes?
Note that the conjugated BA mixes (i.e., MSK-BA2 and MSK-BA2-US) do not contain tauro-β-MCA (TβMCA) and glyco-β-MCA (GβMCA). The rest of the unconjugated BAs have their corresponding conjugated BA pair.
What is the difference between conjugated and unconjugated BAs? The synthesis of conjugated BAs takes place in the liver. The conjugated BAs have glycine (NHCH2CO2H) or taurine (NHCH2CH2SO3H) positioned at the R5 group (see structure in FAQ #1). These are referred to as glycoconjugated and tauroconjugated bile acids, as in the case of glycocholic acid (GCA) and taurocholic acid (TCA), both of which are present in MSK-BA2.
How were the BA mix concentrations assigned? The reported concentrations of the unlabeled BAs in human plasma were used as a reference, with the spiking concentrations of unlabeled BAs used in the Waters MetaboQuan-R™ BA method (see Stable Isotope Standards for Waters MetaboQuan-R™ Methods catalog) also factored for additional utility. Overall, the concentration of 100 µM is considered an appropriate stock concentration, offering end user flexibility for standard preparations in sample analysis and QC testing.
How have the BA mixes been measured? The mixes have been measured in a few different manners, individually and in various ratio combinations (see reference list below). In an example, the mixes were reconstituted in 50% methanol then analyzed directly or following dilution (e.g., at 1 µM) individually or in combination by RPLC-MS/MS (e.g., negative ESI).
What sample types are possible in BA analysis? A multitude of samples are possible in this line of research. These include biofluids (e.g., serum, plasma, urine, feces, intestinal fluid) and tissues (e.g., adipose, gallbladder, kidney).
Example References
McMillan, A.S.; Zhang, G.; Dougherty, M.K.; et al. 2024. Metagenomic, metabolomic, and lipidomic shifts associated with fecal microbiota transplantation for recurrent Clostridioides difficile infection. mSphere, 9(10), e0070624-e0070650. PMID: 39377587
Engevik, M.E.; Thapa, S.; Lillie, I.; et al. 2024. Repurposing dried blood spot (DBS) device technology to examine bile acid profiles in human dried fecal spot (DFS) samples. Am J Physiol Gastrointest Liver Physiol, 326(2), G95-G106. PMID: 38014449
Stewart, A.K.; Foley, M.H.; Dougherty, M.K.; et al. 2023. Using multidimensional separations to distinguish isomeric amino acid-bile acid conjugates and assess their presence and perturbations in model systems. Anal Chem, 95(41), 15357-15366. PMID: 37796494
Foley, M.H.; Walker, M.E.; Stewart, A.K.; et al. 2023. Bile salt hydrolases shape the bile acid landscape and restrict Clostridioides difficile growth in the murine gut. Nat Microbiol, 8(4), 611-628. PMID: 36914755