Single Dimensional Gels
Most samples for SDS-PAGE are acceptable for submission. Samples may be supplied as liquid samples or lyophilized powders. Samples containg guanidine or dissolved in organics (DMSO) are not acceptable. Samples dissolved in urea are acceptable. Typically, 1 – 35 ugm of protein are required depending upon the needs of the analysis. Please consult with the PCL staff for further information regarding sample preparation.
2 Dimensional Gels
Samples for IEF can be submitted as liquid samples or lyophilized powders. Liquid samples must be relatively free of non-protein contminants. Salts, in particular, must be eliminated or at very low concentrations. Ionic detergents must be avoided as well as any ionic buffering agents. These materials must be removed from samples either by dialysis or precipitation. Keep in mind, however, that these methods can result in sample loss. Lyophilization requires prior dialysis so that salts are not concentrated.
The PCL has run validation experiments to illustrate the effects of salts on the performance of the 2D gel (see FAQ). In addition, we have run validation experiments on precipitation techniques to help you visualize the degree of sample loss when comparing acetone and TCA methods against non-precipitated methods (see FAQ). Molecular weight cutoff membranes may also be used but be mindful that proteins may bind.