Mass Spectrometry

Surface Plasmon Resonance (SPR) is an optical phenomenon that is used for the label-free analysis of the binding of any two molecules in real-time.

Hexapeptide libraries, such as Bio-Rad’s ProteoMiner™ protein enrichment technology, can significantly increase sensitivity of shotgun proteomics analyses of diverse complex samples. Underlying this increased sensitivity is the partial removal of high-abundance proteins leading to an increased representation of low-abundance proteins — a phenomenon described as dynamic range compression. Currently, hexapeptide libraries have been mostly used to increase proteomic detection in fluid samples (eg: saliva, plasma, etc.), but not in cellular lysates.

2-D electrophoresis is a multistep technique that separates proteins first by a protein’s isoelectric point and then by its molecular weight. This powerful technique can separate thousands of proteins in a complex proteome and is useful for applications such as protein profiling and biomarker discovery. The drawback of the technique is that it requires multiple steps, each of which can be time-consuming and can contribute to problems with reproducibility.

This tech report compares in-gel and off-gel separation of proteins in terms of overall speed and simplicity of the workflow, resolution of the separation, and depth of proteome coverage provided. Results found that as well as higher peptide yields, in-gel separations were better suited to take full advantage of downstream analysis methods.

This tech report demonstrates the advantages of independently controlled voltage and current parameters for each focusing tray in optimizing IEF conditions for a complex, insoluble membrane protein fraction.