Immunoaffinity Depletion of Highly Abundant Proteins for Proteomic Sample Preparation

Plasma/serum samples pose specific challenges for proteomic profiling. Complexity of these samples consisting of more than 15,000 proteins (3020 core proteins) is one reason, however this is further complicated by a dynamic range of concentrations of twelve orders of magnitude. The latter property of serum/plasma samples requires elimination of highly abundant proteins to enable quality identification and quantification of low abundant proteins. Removal of most abundant proteins such as serum albumin is accomplished by affinity (also immunoaffinity) techniques, however, protein-protein interactions, whether specific or not, will cause removal of some proteins that can be found in albuminome, a fraction of affinity removed serum albumin. Affinity depletion techniques are discussed together with such aspects as reproducibility and quality control. A list of human plasma proteins co-immunodepleted with albumin is provided.