| abstract |
The present invention relates to a method for quantitative detection of a protein of interest in a sample, wherein the second generated fragment ions are detected to provide a series of quantitative measurements, at least one of the amount of proteogenic peptide generated and the target in the sample. The selected first generated fragment ion having a mass (m / z) 2 , which is correlated with the amount of protein of, is a double charged peptide with proline and / or histidine at position 1. |