LC-MS/MS (Liquid Chromatography–Tandem Mass Spectrometry)

LC-MS/MS (Liquid Chromatography–Tandem Mass Spectrometry) has become one of the most powerful analytical tools in modern clinical diagnostics. It combines liquid chromatography (separation of compounds) with mass spectrometry (precise molecular detection) to identify and quantify biomolecules in biological samples with exceptional accuracy.

Because of its high specificity (ability to distinguish very similar molecules) and high sensitivity (ability to detect extremely low concentrations), LC-MS/MS is increasingly used as the reference method (most reliable analytical technique) for many diagnostic tests.

Why LC-MS/MS is Important in Diagnostics

1. Highly Accurate Biomarker Measurement
LC-MS/MS measures molecules directly based on their mass-to-charge ratio, minimizing interference from similar compounds. This leads to highly precise and reproducible results, which are essential for clinical decision-making.

2. Detection of Low-Concentration Analytes
Many clinically important biomarkers occur at very low concentrations in blood or urine. LC-MS/MS allows detection of these analytes with extremely low detection limits.

3. Superior Specificity Compared to Immunoassays
Traditional immunoassays can sometimes suffer from cross-reactivity (false signal from similar molecules). LC-MS/MS provides structural identification, ensuring accurate analyte measurement.

4. Simultaneous Multi-Analyte Testing
LC-MS/MS can analyze multiple compounds in a single run, increasing laboratory efficiency and reducing sample volume requirements.

Why LC-MS/MS is preferred over Immunoassays?

Both Immunoassays and LC-MS/MS can be used for measuring analytes in biological samples, however, LC-MS offers following advantages over immunoassays

Higher Specificity & Sensitivity
LC-MS/MS effectively reduces background noise, resulting in lower limits of detection and quantification compared to traditional methods.

Reduced Matrix Interference
It is less susceptible to cross-reactivity with other substances (e.g., metabolites, structurally similar compounds), which can cause false-positive/negative results in immunoassays.

Multiplexing Capabilities
A single LC-MS/MS run can detect and quantify multiple analytes simultaneously, whereas immunoassays typically require separate tests for each analyte.

Reliability for Small Molecules
It is considered the "gold standard" for measuring steroids, drug screening, and small metabolites, overcoming the limitations of antibody binding.

Wide Dynamic Range
It is effective at quantifying analytes across a broad concentration range. 

Tests Offered by MDRC Using LC-MS/MS Instruments 

• Therapeutic Drug Monitoring
• Newborn Screening for Inborn Errors of Metabolism
• Confirmation of Inborn Errors of Metabolism
• Urine citrate levels
• Gut microbiome health assessment
• Methylation status analysis
• Omega3 : Omega6 fatty acid ratio in RBS membrane
• Depression assessment panel
• Autism Assessment Panel
• Neurotransmitter and Catacolamine Assessment
• Fat & Water-Soluble Vitamins Panel
• High-Precision Assessment of Vitamin D Status
• Drugs of Abuse levels
• NAD+/NADH Ratio (Cellular & Redox and Metabolic Health Marker)
• GSH/GSSG Ratio (Redox Balance and Oxidative Stress Marker)