What Is an Electrophorus?

Under the action of an electric field, a charged particle moves toward an electrode opposite to its electrical property, which is called electrophoresis (EP). The technique that uses charged particles to move at different speeds in an electric field to achieve separation is called electrophoresis.

Electrophoresis refers to the phenomenon that charged particles or molecules move in an electric field, called electrophoresis.

1. PH of electrophoresis medium

The pH value of the solution determines the degree of dissociation of the charged substance, and also determines the net charge of the substance. For proteins, amino acids, etc.

The electrophoresis methods currently used can be roughly divided into three categories: microelectrophoresis, free interface electrophoresis and zone electrophoresis. Zone electrophoresis is widely used, and zone electrophoresis can be divided into the following types:

According to the physical properties of the support, zone electrophoresis can be divided into:

(1) Filter paper is a support

The instruments required for electrophoresis are: electrophoresis tank and power supply.

1. Electrophoresis tank

The electrophoresis tank is the core part of the electrophoresis system. According to the principle of electrophoresis, the electrophoresis support is placed between two buffers.

1. Polyacrylamide gel electrophoresis can be used as protein

For different purposes, different detection methods should be used. The combination of dyes and biological macromolecules to form colored complexes is the most common method for detection after electrophoresis.

(VII) Abnormal phenomena and countermeasures of polyacrylamide gel electrophoresis

1. The leading edge of the indicator appears to be up or down on both sides. The upward "smile" phenomenon indicates that the gel is cooled unevenly, and the middle part is not cooled well, so the molecules in the gel have different mobility. This often happens with thicker gels and vertical electrophoresis. The downward "frowning" phenomenon is often caused by the inadequacy of the device of the electrophoresis tank during vertical electrophoresis, especially when the bottom of the "sandwich" consisting of gel and glass plate or the gel polymerization near the separator is not complete This phenomenon occurs.

2. "Smearing" is the most common phenomenon in electrophoresis. This is often caused by poor sample dissolution. The solution to this problem is to centrifuge the sample before adding the sample, choose the appropriate sample buffer and gel buffer, and add solubilizing auxiliary reagents. Another method is to reduce the gel concentration.

3 The "texture" phenomenon is often caused by insoluble particles in the sample. The solution is to increase the solubility and centrifuge to remove the insoluble particles.

4 Protein band skew is often caused by non-parallel placement of filter paper strips or electrodes, or due to skewed sample application locations.

5. The protein band is too wide and is connected to the protein band of the adjacent protein lane, which is caused by too much sample loading or leak in the sample well.

6. The blurring and poor resolution of protein bands are caused by a variety of reasons. Although gradient gels can improve resolution, conventional polyacrylamide gel electrophoresis is a lower resolution method compared to other methods. In order to improve the resolution, do not add too much sample. Small volume samples can give narrow bands. Electrophoresis should be performed immediately after loading to prevent diffusion. Select the appropriate gel concentration to allow adequate separation of the components. Generally, the resolution of protein bands near the leading edge is not good, so a gel of sufficient length should be poured according to the relationship between molecular weight and gel pore size so that the sample does not go out of the leading edge. Proteolysis of the sample also causes diffusion and reduces resolution. Hydrolysis usually occurs during sample preparation. The endogenous protease in the system will hydrolyze the sample protein. Adding a protease inhibitor to the buffer can reduce this situation.