A deep understanding of metabolic and lipidomic data is crucial for comprehending plant, bacterial, and mammalian biology. This omics-based research has developed over the last four decades and is now utilized to gain valuable insights into epidemiological, pharmacological, drug toxicological, disease biology, and patient stratification studies. LC-MS assays have become the primary choice of technology for lipid and metabolic profiling. It provides sensitivity, speed, and structural and molecular elucidation capabilities.
In the last two decades, LC-MS assays have witnessed several methodological and technological advances, leading to the development of a reliable, rugged, and easily deployable tool. These advances include improvements in chromatography and mass spectrometers, data analysis tools, optimized sample preparation, harmonized protocols, introduction of ion mobility, quality control methods, and much more. The current article discusses LC-MS method development for biomarker discovery in large cohorts. Similar to reliable ELISA testing services, LC-MS labs are focused on providing robust LC-MS method development and validation services.
LC-MS method development for high throughput analysis
Early applications of LC-MS assays for profiling urine and blood metabolites were relatively low to moderate throughput and with moderate resolutions. Most of these early applications of LC-MS-based systems used columns with particle sizes of 3.5 or 5 micrometers and gradient elution of around 10 to 25 minutes. These parameters yielded a 6 to 10-second wide chromatography peak at the base and around 100 units of separation capacity. For small-scale studies, these parameters are perfectly adequate. However, studies with large cohorts that require longer runtimes and analysis of hundreds of samples are challenging.
With time, LC-MS assays were upgraded using fluorescence and ultraviolet detection with better column and gradient elution to include high throughput analysis. Hence, researchers started adopting LC-MS systems for high throughput analysis in plant and human biology studies. Besides, with the advent of ultra-high-performance liquid chromatography, the optimal mobile phase velocity increased up to threefold compared to traditional HPLC systems. Besides a dramatic increase in resolution, ultra-high-performance liquid chromatography provided analysis times of 10 to 15 minutes, directly increasing sensitivity and detection capacities of mass spectrometers.
Subsequently, a research in 2015 developed and optimized LC-MS assays for large-scale metabolic phenotyping. This approach addressed the issue of band broadening and decreased solvent consumption by reducing the column diameter. These features were achieved while maintaining biomarker detection and separation capabilities in rat urine samples. Since then, this approach has laid the foundation for large-scale cohort studies for metabolic phenotyping at high throughput.
Today approaches for reducing band broadening have helped in the growth of ultra-high-performance liquid chromatography for large cohort studies. However, short analysis times and narrow peaks have their challenges, and hence, future directions and initiatives are crucial for reducing challenges with MS detection and autosamplers.
In Conclusion
The last decades have seen numerous advances in LC-MS-based techniques. These developments have enabled researchers to perform multiple biomarker-based large cohort studies. With each decade, scientists have invented significant features such as improved MS methodologies and increased assay sensitivity for characterizing and identifying potential biomarkers. However, a collaborative approach is critical to take LC-MS systems to the next step for high throughput large cohort studies.
