Polyacrylamide gels sample application

See also Blood and Plasma. Capillary Electrophoresis Overview. Cerebrospinal Fluid. Clinical Analysis Sample Handling. Electrophoresis Principles Isoelectric Focusing Polyacrylamide Gels Clinical Applications. Immunoassays Overview. Immunoassays,... 

Zonal techniques are the most frequently used form of electrophoresis and involve the application of a sample as a small zone to a relatively large area of inert supporting medium which enables the subsequent detection of the separated sample zones. A wide range of supporting media have been developed either to eliminate difficulties caused by some media (e.g. the adsorptive effects of paper) or to offer additional features (e.g. the molecular sieving effects of polyacrylamide gel). 

In protein electrophoresis, a sample is applied to a polyacrylamide gel and its protein components are separated by application of an electric field across the gel. Separation is dependent on the charge and size of the proteins in the sample. Different approaches to this method have been developed to suit a variety of purposes. 

Figure 5 also shows two 10-hr samples, 10a and 10b. Sample 10a was stored in solution at 4°C for one week, while sample 10b was stored frozen and then thawed immediately before application to the polyacrylamide gel. Both samples show the same protein band pattern. If proteolytic enzymes in the culture filtrate had acted on and partially degraded the extracellular proteins, a different band pattern would have been expected. Thus no product-precursor relationship appeared to exist between the various extracellular proteins in a culture filtrate of Thermoactinomyces. Moreover, it seems as if this organism produces at least three different extracellular cellulolytic enzymes simultaneously. 

The application of CE-LIF using intercalating dyes TOTO-1 and YOYO-1 (with a sample prestaining procedure) and separation systems employing either polymer network (0.5% methylcellulpse) or cross-linked polyacrylamide gel (3%T, 3%C) was also reported by Srinivasan et al. (1993). Excellent sensitivity (about 500 pg/mL) was reported besides, it was found that the polymer network capillaries have a broader DNA size range of effectiveness and provide higher resolution and efficiency than gel-filled capillaries. 

The following five proteins, which are listed with their molecular weights and isoelectric points, were separated by SDS-polyacrylamide gel electrophoresis. Give the order of their migration from the top (the point of sample application) to the bottom of the gel. 

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