Spectral Counting Label-Free Proteomics

Label-free proteome quantification methods used in bottom-up mass-spectrometry based proteomics are gaining more popularity as they are easy to apply and can be integrated into different workflows without any extra effort or cost. In the label-free proteome quantification approach, samples of interest are prepared and analyzed separately. Mass-spectrometry is generally not recognized as a quantitative method as the ionization efficiency of peptides is dependent on composition of peptides. Label-free quantification methods have to overcome this limitation by additional computational calculations. There are several algorithms available that take into account the sequence and length of the peptides and compute the predicted abundance of proteins in the sample. Label-free methods can be divided into two categories: peptide peak intensity based quantification and spectral counting quantification that relies on the number of peptides identified from a given protein.

Source: Springer protocols feed by Protein Science - May 6, 2014 Category: Biochemistry Source Type: news