Quantitative Amino Acid Profiling Using the Kairos Amino Acid Kit and MetaboQuan-R

Importance of the Topic

Amino acids are fundamental to protein structure and biological function. Their precise quantification is essential across biomedical research, clinical diagnostics, and nutritional studies. Reliable amino acid profiling informs on metabolic status, disease biomarkers, and therapeutic targets.

Objectives and Study Overview

The study aimed to evaluate the performance of the Kairos Amino Acid Kit combined with the MetaboQuan-R high-throughput LC-MS/MS platform. The goal was to establish a rapid and reproducible workflow for quantitative profiling of amino acids in biological samples.

Methodology and Instrumentation

• Sample Preparation: Serum samples underwent protein precipitation using sulfosalicylic acid with stable isotope labeled internal standards. Derivatization was performed with AccQTag reagent before analysis.
• Chromatographic Separation: Derivatized amino acids were separated on an ACQUITY UPLC I-Class system with a CORTECS T3 column at 60°C. A gradient elution from 1 to 8% organic solvent over 2.4 minutes ensured efficient resolution of isobaric species.
• Mass Spectrometry: Detection utilized a Xevo TQ-S micro in positive electrospray ionization mode. Multiple reaction monitoring transitions were optimized for 29 derivatized amino acids, achieving high sensitivity and specificity.

Used Instrumentation

• ACQUITY UPLC I-Class System with Fixed Loop
• CORTECS T3 2.7 μm Column (2.1 x 30 mm)
• Xevo TQ-S micro Mass Spectrometer

Main Results and Discussion

The workflow demonstrated excellent linearity with correlation coefficients greater than 0.995 across a broad dynamic range. Calibration curves for key amino acids such as glutamine, lysine, and tyrosine showed r2 values above 0.999. The platform successfully resolved isobaric compounds, overcoming common limitations of flow injection methods.

Benefits and Practical Applications

• High Throughput: Rapid analysis with a total run time under 5 minutes per sample.
• Reproducibility and Accuracy: Standardized consumables and stable isotope labeled internal standards improved quantitation precision.
• Versatility: Applicable to diverse biomedical research areas, including metabolomics, nutritional studies, and clinical diagnostics.

Future Trends and Potential Applications

Advancements in multiplexed derivatization reagents and enhanced mass spectrometry hardware may further reduce analysis time and expand compound coverage. Automation of sample preparation and data analysis will facilitate large-scale clinical studies and real-time metabolic monitoring.

Conclusion

The combined Kairos Amino Acid Kit and MetaboQuan-R LC-MS/MS workflow provides a robust, rapid, and accurate solution for quantitative amino acid profiling. Its high specificity and reproducibility make it ideally suited for advanced biomedical research and diagnostic applications.

References

No references cited in the original document.