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Metabolic Research

QReSS™ Kits

Standardizing Quantitative Metabolomics Analyses Through the QReSS™ Kit (Application Note 49)

  • Standardizing Quantitative Metabolomics Analyses Through the QReSS™ Kit (Application Note 49)
  • Metabolomics QReSS™ Kit

To ensure high-quality metabolomics results, the method and instrument system must be qualified as being fit for purpose. This involves testing for losses or errors in the analytical workflow. To aid such performance assessments in MS metabolomics and simultaneously enable metabolite quantification, CIL is pleased to offer the QReSS™ (Quantification, Retention, and System Suitability) kit. This is well suited for such applications, as demonstrated through collaborative work with Sciex, due to the carefully selected compounds and their inherent characteristics (e.g., molecular weight), as well as their experimental tendencies (e.g., broad elution behavior, absent from solubility issues or stability concerns). Please refer to the Metabolomics QReSS Kit flyer for mix composition details and an overview of the validation/applications.

Kit contents:
  • Two vials of dried-down metabolite mixes (stable isotope-labeled, MSK-QReSS-KIT or unlabeled, MSK-QReSS-US-KIT).
  • Document package (supplied via QR code). Package includes user manual, which contains example procedures and LC-MS methods for user reference.


  Metabolomics QReSS™ Kit

  Metabolomics QC Kits

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

  Stable Isotope Standards for Mass Spectrometry

  Standardizing Quantitative Metabolomics Analyses Through the QReSS™ Kit (Application Note 49)



Frequently Asked Questions 

How were the metabolites in the QReSS mixes selected?

A combination of factors were involved in the panel selection. This related to the nature of the metabolites themselves (e.g., molecular weight, compound class, stability), their availability, and elution pattern in a chromatographic test method. More specifically, compounds that provided a spread of characteristics and were available under certain labeling requirements (M+3 minimum, if possible), while posing no solubility or stability concerns once formulated into a mix or added to a matrix (e.g., human plasma) were considered.

What is an example solvent for reconstituting the dried-down mixes?

The mixes can be solubilized in 1 mL of water:methanol (50:50 v/v). Doing so will yield the concentrations specified in the QReSS kit flyer.

Why are the concentrations not constant across the metabolite panel?

The concentrations are variable as they have been balanced relative to those found in a biological matrix. Specifically, using an example metabolomics workflow, the labeled metabolites were found to be within an order of magnitude of their unlabeled analogues in a normal, pooled human plasma sample.

On what platform has the mix validations been performed?

Through collaboration with Sciex, both targeted and untargeted LC-MS/MS was used to qualify the QReSS mixes. Targeted, for instance, was performed by RPLC-MRM/MS on a QTRAP 6500+. The column employed was a Kinetex F5 UHPLC (150 x 2.1 mm, 2.6 µm).

Can a custom add-on vial be formulated?

We will evaluate all requests provided that certain compound details are supplied (see custom mix request form). Please complete and submit this form online or contact your local sales representative.

Krista Backiel

Krista Backiel

Marketing Manager and Metabolomics 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

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.