MRMSRMSequenzen

MRMSRMSequenzen, also known as Multiple Reaction Monitoring (MRM) and Selected Reaction Monitoring (SRM), are highly sensitive and selective techniques used in mass spectrometry for the targeted quantification of specific molecules. These methods are particularly valuable in fields such as proteomics, metabolomics, and pharmaceutical analysis, where the accurate measurement of low-abundance compounds is critical.

The core principle of MRM/SRM involves selecting a target molecule, often a peptide or a small molecule, and then monitoring specific fragmentation patterns within the mass spectrometer. First, the precursor ion of the target molecule is isolated in a quadrupole. This precursor ion is then fragmented in a collision cell. Finally, specific product ions, which are characteristic of the target molecule, are selected and detected in a second quadrupole or detector. By monitoring these unique precursor-to-product ion transitions, researchers can differentiate and quantify the target analyte even in complex biological matrices.

The selectivity of MRM/SRM arises from the sequential isolation and detection of specific ions. This makes the technique highly robust against background noise and interference from other molecules. The sensitivity is achieved by focusing the instrument's detection capabilities on a limited number of specific transitions, allowing for the detection of analytes at very low concentrations. The quantitative accuracy of MRM/SRM is further enhanced by the use of isotopically labeled internal standards, which are co-injected with the sample. These standards have the same chemical properties as the analyte but a different mass, allowing for precise correction of sample preparation losses and matrix effects.