Products for Digestion

Trypsin Digestion

Obtaining a complete trypsin digestion requires complete solubilization, reduction, and alkylation of the extracted proteome. These have been difficult requirements, as the best solubilizing and reducing agents available interfere with the activity of the trypsin enzyme. Additionally, the strong solubilizing agent SDS is well known for its ability to cause problems later on during sample separation and detection. Therefore, many researchers have become resigned to settling for “good enough” trypsin digests. But now that these researchers want to expand their inquiries into the less-soluble components of the proteome, and use quantitative mass spectrometry methods to analyze protein activities, incomplete trypsin digests are no longer good enough. Incomplete digests may or may not be biased with respect to the protein, or proteins, of interest, but when bias occurs, it’s typically the important membrane proteins that are left out.

Fortunately, recent methods development research carried out separately in the laboratories of Daniel Liebler and Matthias Mann has resulted in the development and optimization of the extraordinarily useful and convenient FASP (filter-aided sample prep) method of preparing extracted proteomes for analysis by mass spectrometry. Among other advantages, FASP permits the use of lysis and solubilizing buffers with high concentrations of strong detergents and reducing agents. Researchers no longer need to settle for partial, irreproducible trypsin digests.

The FASP Proteomic Reactor

Filter-Aided Sample Preparation (FASP) is a protein sample preparation method which collapses solubilization, detergent depletion, enzymatic digestion, and peptide purification into a single protocol. All of the steps involving the protein sample are carried out within a “proteomic reactor” composed within a spin filter. Among other advantages, the FASP method introduces a practical, mass spectrometry-compatible way to exploit the solubilizing capability of SDS within the context of a shotgun proteomics experiment.

The FASP method is now available in the form of a convenient and economical kit. Visit Protein Discovery’s FASP Protein Digestion Kit product information page.

FASP for FFPE Proteomics

FFPE-FASP is a straightforward extension of FASP which makes the method suitable for preparing formalin-fixed, paraffin-embedded tissue sample proteins for analysis by mass-spectrometry. Get information about Protein Discovery’s FFPE-FASP Protein Digestion Kit.