Which company does a better job in antibody purification services?

Jin Kairui Biotech provides customers with rabbit, sheep, guinea pig, chicken eggs and other species** polyclonal antibody purification technology and mouse monoclonal antibody purification technology. Antibody Fab fragment preparation is also available for customers. The purity and activity of the antibody will directly affect the success or failure of the experiment, and Jin Kairui will select the best purification method according to the customer's specific use to solve the problem of somatic antibody purification for the customer.

ABCOM, Shanghai Wenyuan Pavilion, Suzhou Lisui, only know these.

The preparation of highly specific and high-potency antibodies is the basis of experimental immunology technology, and the quality of antibodies will directly affect the success or failure of the experiment. Antibodies prepared by different methods are often mixed with multiple impurities, and antibody purification is required in order to obtain relatively single antibodies or to use antibodies for specific purposes. From the perspective of composition, antibody molecules are a class of protein molecules, which, like other proteins, have certain isoelectric points, solubility, chargeability and hydrophobicity, and can be separated and purified by electrophoresis, salting-out precipitation or other chromatography techniques.

Purified antibodies are often used to detect antigens directly. At this point, the antibody is labeled with an easily identifiable marker that binds to and detects the antigen being studied. In the indirect antigen detection method, the primary antibody is not labeled, but is detected with a labeled secondary antibody (an anti-immunoglobulin antibody).

In general, the indirect method is recommended. Because many businesses are able to provide reliable conjugated secondary antibodies, the indirect method not only saves effort, but also provides reliable results. Nonetheless, there are several methods that require labeled primary antibodies.

For example, in immunostaining assays, when the relative positions of two or more antigens need to be studied, it is often necessary to purify the antibody and label it with different markers so that their relative positions can be compared. In this case, it is not appropriate to use the indirect method. This is because the indirect method uses a labeled secondary antibody to localize the unlabeled primary antibody.

For example, when the primary antibody needs to be labeled, and there are a large number of extraneous antibodies in the sample that can interfere with the detection of the primary antibody, an indirect method is not appropriate. This is also the case when murine tissue antigens are localized with murine monoclonal antibodies. At this point, the primary antibody needs to be purified and labeled directly as described below.

A method for purifying antibodies by the caprylic acid method.

At the time of precipitation, the protein concentration should be about 10 mg ml, the serum protein concentration should be about 50 mg ml, and caprylic acid should be added according to 3ul ml.

At this concentration, caprylic acid will not precipitate the antibody, but will precipitate other miscellaneous proteins, and then precipitate the antibody with a certain concentration of ammonium sulfate to achieve the purpose of further purification, generally 30 ammonium sulfate or a little higher.

If caprylic acid is added too much, then the antibody will precipitate together with other miscellaneous proteins, and the caprylic acid may cause damage to the structure of the antibody.

The only way to remedy this is to centrifuge the pellet and reconstitute it, and then re-add the caprylic acid precipitate.

What is the difference between a protein purifier and a protein purification analyst?

Protein purification is only a technology, the design is still biased towards technology, and the market is not closely connected, and there are very few professional companies, and the application type is not as good as in vitro diagnosis.

As for the development of your good or bad, do technical people, or rely on the strength of technology, if it is the market, that is their own market acumen, 1Biopharmaceutical companies: such as the purification of protein products, the purification of various vaccines, etc., can be done in technology, but also in sales.

2.Scientific research institutions: such as local biological institutes, etc.

3.Service outsourcing company: specializing in providing purification services (including processes and products) such as proteins and vaccines

4.Companies that produce protein purification media: Such companies generally need to test and verify the performance of the produced media.

5.If you have the funds and projects, it is also a good choice to start your own business.

6.Of course, it is not only limited to the above-mentioned ways of working, but also depends on one's own interests and hobbies, and it is not excluded to engage in other industries, and there are many successful cases of cross-industry work.

You can try Shanghai Bogelon, which is much cheaper than GE, and the quality of their Rprotein A media is still very good.

The protein purification medium of Changzhou Tiandiren is good, and it is not expensive.

The principle of all purification is that I keep what I want and get rid of what I don't want. The ideal is 100% purity and 100% yield.

But everyone knows it's impossible.

Antibody purification is mainly based on type and requirements. For example, for monoclonal antibodies, after a protein A or G protein column is pure enough. In the case of secondary antibodies, they can be purified with immunoglobulins.

Peptide antibodies can also be purified with peptide antigens. If it is a cytokine-immunized polyantibody, because cytokines are too expensive, it can also be purified with a protein A or G protein column, or simply purified with ammonium sulfate.

You can ask some domestic antibody companies to find a similar antibody and ask them what method of purification.

Also, depending on what you do for it, the purity requirements for this antibody are also different. The other is the loss of antibody amount during the purification process, the loss of activity, etc.

1. Do not inactivate the antibody. Avoid antibody denaturation.

2. Depending on the downstream purpose of your purified protein, purity requirements are important.

The antibody isotypes targeted by Protein A and Protein G are not identical.

There are several types of antibody purification, and depending on the application, the method to choose for purification is decided:

1.Crude purity: The serum or ascites fluid and cell supernatant for the preparation of antibodies are directly processed by salting-out method, so that other impurities in these substances can be removed and protein components can be obtained, but because it is crude and pure, there will be a large number of other proteins mixed in it, so that the antibody obtained is of low purity and has a relatively high background in the experiment.

2.Universal purification: Protein A, Protein G, or Protein L is conjugated with an antibody.

Because different antibodies** have different binding abilities and these antibody-binding proteins, it is necessary to choose which antibody is best to use according to the antibody**. For some single-chain antibodies, protein L is most likely used for purification. After the affinity purification of the antibody-binding protein, only the components of the antibody are basically retained in the solution, and the other proteins are removed, and the purity of the antibody can be relatively high.

Relatively speaking, this method is the most commonly used purification method in large-scale antibody production, and many antibody companies use this method to purify antibodies.

3.Specific purification: However, some antibodies need to be of particularly high purity and specificity, so they cannot be purified simply by the above two methods.

Antibodies must be purified by preparing antigen fixation into specific affinity cartridges. At this time, all you get is antibodies against one antigen, and the specificity is the best. Of course, due to the involvement of operations such as antigen fixation, the cost is correspondingly the highest.

Currently, antibody purification is divided into 3 steps.

1. Capture: Usually use Protein A or G, the cost is relatively high, at present, Pall company has a MEP filler, which can replace Protein A or G, **only one-eighth of Protein A, there are already antibody companies in China using this filler for production, especially recommended.

2. Ion exchange: The performance of each brand is almost the same.

3. Removal of polymers, etc.: GE, Bio-Rad CHT, PALL mixed-mode fillers are OK, I have a report on the removal of polymers from these brands of fillers, and I need to write an email to me

Antibodies can be purified using Shanghai Biotech's SF024-NHS with antigen twisting.

In general, in order to maximize the specificity of co-immunoprecipitation, it is best to use purified antibodies, because there are too many impurities in the serum, which is very easy to cause non-specific adsorption.

Of course, if you are doing the interaction of overexpressed recombinant proteins, and you are only doing verification work, you can also try it with serum. However, there may still be a problem with high background.

In fact, the most critical point that determines the success or failure of immunoprecipitation is the quality of the antibody, including purity and specificity.

What is this step? In this case, his operation step is to use it first, and then according to his results.