Electrophoretic Separation Media

Electrophoresis can be performed in free solution, but thermal and diffusional mixing are usually too great to give satisfactory resolution of the components. It has long been recognized that it is usually necessary to use some type of static support in order to contain the background electrolyte, contain the sample and limit diffusion. The primary function of the stabilized support media is to limit the dispersion that results from convective disturbances. The stabilization should not change the mobility of the ions significantly provided that neither absorption onto the support occurs nor do large analytes become physically trapped.

Over the years a large number of supports have been used as stabilizing media, but relatively few satisfy all the criteria for the ideal support (Figure 8). These criteria are a reproducible structure, good mechanical strength, ease of formation into appropriate shapes, chemically inert to both the electrolyte and the analytes, no thermal degradation and minimal background in the detection processes. The earliest support was probably cellulose in the form of sheets of laboratory filter paper. Kunkel and Tiselius published the classic study on paper electrophoresis in 1951. Cellulose acetate membranes have large pores and do not retain proteins either chemically or physically. It is the preferred membrane for serum protein separations.

Paper

Glass (beads and powder) columns and silica-gel plates Cellulose powder, cellulose acetate, nitrocellulose

— Natural products-

Gels

— Synthetic materials-

-Agar — Agarose - Polyacrylamide

Figure 8 Common stabilized media used in electrophoresis.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

Get My Free Ebook


Post a comment