Carrier Ampholytes

The pH gradient formed by the carrier ampholytes during IEF can be affected by the amount of total protein loaded. Proteins when applied in large quantities, having themselves a buffering capacity, can affect the focusing position along the pH gradient and consequently the reproducibility. Therefore, factors such as protein quantity, temperature, voltage and chemicals can strongly affect performance. Only small quantities of protein (of the order of 0.1 mg) should be applied for IEF with the carrier ampholytes approach. The difficulties in controlling the various factors which affect reproducibility together with the difficulties of preparing and transferring the tube gels to the second dimensional separation, contribute to the reasons why carrier ampholyte-based IEF remained a scientific speciality of only a few laboratories. Nevertheless, these laboratories are able to control the conditions affecting reproducibility, so that IEF with carrier ampholytes is still used. This approach allows a very reliable protein quantification of complex mixtures. Because only a small amount of protein can be applied, 2D gels made following the carrier ampholyte approach are more suitable for analytical purposes. IEF based on carrier ampholytes can efficiently separate proteins with pis within the pH range of 3-8. Proteins with higher pIs separate poorly due to cathodic drift during isofocusing. The cathodic drift is the result of a high electroosmotic flow, caused by the charged groups on the glass walls of the gel tubes.

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.

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