Bile Acid Mixtures

Metabolomics Bile Acid Mixtures

Metabolomics Bile Acid Mixtures

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).

To aid research and development efforts in this space, CIL is pleased to offer stable isotope-labeled and unlabeled BA mixes. These dried-down mixes are available with the unconjugated BAs in one vial (labeled, MSK-BA1-1; unlabeled, MSK-BA1-US-1) and the conjugated BAs in a second vial (labeled, MSK-BA2-1; unlabeled, MSK-BA2-US-1). Please refer to our Metabolomics Bile Acid Mixtures flyer for the mix compositions.

Resources

Metabolomics B ile Acid Mixtures

Mixtures, Sets, and Kits for MS ‘Omics and MS/MS Screening

Stable Isotope Standards for Mass Spectrometry

Frequently Asked Questions

What are the structures of the bile acids present in these mixes?

Note that the conjugated BA mixes (i.e., MSK-BA2-1 and MSK-BA2-US-1) 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-BA2-1.

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 by our academic/industrial collaborators in a couple different formats. In general, these were reconstituted in 50% methanol then analyzed directly or following dilution (e.g., at 1 µM) by RPLC-MS/MS (e.g., Orbitrap ID-X and Xevo TQ-S micro with negative ESI). The mixes have been analyzed individually and in various ratio combinations.

What sample types are possible in BA analysis?

A multitude of samples are possible in this line of research, with those types stemming from both human and rodent species. These include biofluids (e.g., serum, plasma, urine, feces, intestinal fluid) and tissues (e.g., adipose, gallbladder, kidney).

Krista Backiel

Marketing Manager and Clinical MS Manager

Krista Backiel is responsible for managing and promoting products that are utilized in metabolomics and clinical/diagnostic MS. She spends a lot of her time developing new products to assist customers in their diverse research efforts.

Andrew Percy, PhD

Senior Applications Chemist – Mass Spectrometry

Dr. Andrew Percy is the Senior Applications Chemist for Mass Spectrometry and the MS ‘Omics Product Manager at CIL. His responsibilities minimally involve providing technical support, overseeing product development, identifying new product market opportunities, assisting in the analysis of product-related applications, and writing/reviewing marketing literature.

Metabolic Research