Are you thinking about replacing existing immunoassay technology with clinical mass spectrometry?  Keep reading to discover how the 3 “S”s will help you make the decision.

1. How does sensitivity play a role?

Many of the analytes measured in a clinical chemistry lab exist at nanogram and picogram per milliliter levels.  We’re talking parts per billion and parts per trillion territory.  Antibody-based applications might struggle to accurately detect and quantify biological compounds at such low concentrations, but LC-MS/MS provides the ability to accurately detect analytes at these ultra-low concentrations.

2. Is specificity enhanced when using mass spectrometry?

Whether the immunoassay is based on a monoclonal or polyclonal antibody approach, the compound in question is being detected based on the tertiary structure of the molecule.  Because biological compounds such as steroids can have almost identical chemical structures, antibody-based techniques might struggle with molecular specificity.  Mass spectrometry can identify compounds by the fragmentation pattern of the molecule, meaning its characteristic product ions, providing the enhanced specificity needed for the correct identification of structurally-similar compounds.

3. How important is selectivity?

In clinical chemistry, the variety of matrices, such as whole blood, plasma, serum, saliva, and vitreous humor, can make identification a challenge.  Complex matrices can cause problems in methods that are susceptible to interference.  Mass spectrometry uses powerful liquid chromatography to separate the analyte of interest from the matrix and detect and quantify it accurately.  More advanced options such as QTRAP® technology available on the SCIEX Citrine® LC-MS/MS system takes it to another level—handling a matrix such as hair with ease. 

There are many more benefits that mass spectrometry can provide, such as multiplexing to analyze more compounds in a single injection or developing your own assays as Lab Developed Tests (LDTs).