The following information should act as a guide for important steps in performing a proteomics experiment. It is not intended to cover every aspect of an experiment but rather to give suggestions for the major steps involved.
Consultation and careful planning in the beginning will prevent ruining your samples for the whole experiment. Important aspects to monitor so this doesn’t happen are the collection, handling and storage of the samples. This is particularly true in studies involving human patients or animal studies where samples are collected in a clinic or operating room.
Proteins: the storage of tissue for protein isolation will be dependent on the down stream experimental design. However, it is critical that tissue samples be handled such that the proteins of interested will be stabilized as soon as possible following sample collection from the source. This may involve the addition of protease inhibitors, phosphatase inhibitors, reducing agent etc, and rapid storage at -80?C.
Handling and Storage
Proteins: The most important thing to consider once you have freshly isolated protein is how many aliquots do I need to make, how much volume per aliquot and what vessel to use for the aliquots? Some consideration must be made prior to protein isolation on how and where they will be stored prior to use. If your target protein(s) is in low abundance, you might consider using siliconized storage tubes to prevent loss on the tube walls. You would not want to add BSA if you planned to use the samples for Mass Spectrometry analysis, for example. Determine the concentration of your proteins, dilute to a common concentration in the appropriate buffer for downstream analyses and aliquot into the chosen vessels. Store aliquots at -80?C until used.