Custom Analysis

WHAT IS A CUSTOM ANALYSIS?

A custom analysis is the analysis of an analyte or group of analytes that are not already part of our established panels or normal, routine analyses. These can be metabolites, lipids, proteins, synthetic compounds, and more. In many cases it may be possible to simply add the analyte of interest to an existing panel, such as adding a polar metabolite to the Targeted Metabolomics Panel. However, in some cases it will make more sense to develop a separate and standalone method for the analysis of your particular analyte(s) of interest. In this case we can help to develop a custom panel. A custom panel will have an extraction and LCMS method that have been specifically optimized for your analyte(s) of interest and for your particular sample type.

HOW TO GET STARTED?

Setup a Meeting with Us

First thing before embarking on any LCMS analysis is to always reach out to MSF staff to determine the best course of action. Always check our existing panels found on our website to determine whether your analyte(s) of interest are or are not already part of a panel.

Identify Existing LCMS Methods from the Literature

Chances are someone has already analyzed your analyte(s) of interest and has published a research article about it. Search Pubmed or Google Scholar to look for "liquid chromatography mass spectrometry" along with your analyte(s) name. Share any papers you may find with us so we can review the method and determine whether our instrumentation is able to replicate the published method. Developing a custom panel from an existing and published LCMS method will greatly accelerate our ability to have a method up and running to analyze your samples.

Standards

As we begin to develop a custom panel for you we will need chemically pure standards and isotopically-labeled standards to test. Standards are purified, isolated forms of your analyte(s) of interest. If you are interested in absolute quantification (see our explainer on absolute vs. relative quantification here), then we will need isotopically-labeled standards as well. An isotopically-labeled standard will have the same physicochemical properties as the unlabeled analyte of interest except that they will be labeled with heavy atom(s) to increase the mass. The mass spectrometer is able to differentiate the "heavy" standard from the unlabeled, or "light", analyte.

Below is a list of vendors that sell both unlabeled and isotopically-labeled standards:

Matrix

A matrix is the type of sample that will be analyzed containing your analyte(s) of interest. For example, this could be cells, bacteria, tissue, biofluids (blood, serum, plasma, urine, breast milk, etc.), environmental samples, and others. We will use this matrix along with the standards to test and optimize the extraction method and LCMS method parameters. For endogenous analytes (i.e. something that is naturally found in the sample of interest) it may be necessary to use a synthetic matrix or a depleted matrix if one is available.

Test Samples

Once we have a potential LCMS method setup we will need test samples to determine how effective it is. Test samples should be identical to actual samples that will be analyzed and the analyte(s) of interest should cover the expected concentration ranges of actual samples.

CUSTOM ANALYSIS DEVELOPMENT

Extraction Strategies

With the provided matrix and standards, we will test a variety of extraction strategies to maximize recovery and minimize matrix effects. We will also determine the sensitivity, including the limits of detection (LOD) and quantitation (LOQ), and the linear range using the provided standards and matrix.

LCMS Conditions

Optimizing the liquid chromatography (LC) conditions may involve testing different column chemistries, mobile phase compositions or additives, flow rates, gradients, resuspension solvents post-extraction. Each factor can have an influence on the sensitivity of the analyte(s) of interest. For the mass spectrometer (MS) parameters, we will optimize the source conditions, such as ionization voltages, positive vs. negative polarities, source temperature, gas flows to disperse and desolvate LC eluent into the MS.

Validation of LCMS Method

For a complete and full validation of a custom LCMS method, we'll additionally determine the following parameters

  • Accuracy
  • Precision
  • Selectivity & Specificity
  • Sensitivity
  • Carryover
  • Recovery
  • Martix effects
  • Intra- and Interday Reproducibility
  • Stability

EXAMPLES OF CUSTOM ANALYSES

Below are a few examples of custom analyses we have performed:

  • PFAS
  • Thyroid Hormone Analysis
  • Cocaine/Fentanyl Analysis
  • Tacrolimus & Mycophenolic Acid from Whole Blood