Monthly Archives: May 2015

You Know How antibody generate?

You Know How antibody generate?

Topic covered

Summary

Discovery

Physical and chemical properties

Biological Activity

Production

Classification

Summary

Antibody, an immunoglobulin, is generated by the B cells in the antigenic substance’s stimulation. And it can be reacting with special antigen. Antibody molecule are synthesized and secreted by the plasma cells, and each can produce a plasma cell clone specific antibody molecules, so the antibody in serum is mixed by many kinds of antibody molecules.

antibody2

Physical and chemical properties of antibody

In the first 40, Tiselius and Kabat had proved the activity of antibody has something to do with the Globulin in serum. They immunized rabbit with the pneumatically and polysaccharide to get the high-quality immunological serum. So they proved that the activity of antibody has something to do with the Globulin.

The biological activity of the antibody

  1. Specific antibodies and antigen binding antibody production stimulating substance are called an antigen, an antibody and its corresponding antigen molecule binding is called specific binding.
  2. Binding of antibodies and complement, under certain conditions, the antibody molecule may be presented in the serum complement molecules combination and make it activate, produce a variety of biological effects, complement binding phenomenon and it is known as antibody, antibody molecules revealed inter-molecular interactions complement.
  3. The third function of antibodies is antibodies can enhance phagocyte role. In experiments in vitriol, the serum added suspension of necrophiliacs and enhancing phagocytes corresponding cells is called as an antibody conditioning.

The production of antibody

In order to study on the Physical and chemical properties, molecular structure and function, and the application of antibodies in clinical diagnosis, treatment and prevention of antibody, we should produce antibody by human beings. Recently, according to the methods and the rules of preparation, we classify the antibody into three kinds: poly-clonal antibodies, monoclonal antibodies and genetically engineered antibodies.

  1. Poly-clonal antibody

The early conventional antibody preparation method is a natural antigen immunized animals by various routes, as antigenic material with multiple epitopes, it can stimulate the production of a variety of antibody-forming cell clones, synthesis and secretion against various epitopes antibody secreted into the serum or body fluids, it is in fact a mixture of the serum with a variety of antibodies, such known serum by in vivo immunization of the obtained poly-clonal antibody, it is the first generation of antibodies.

  1. Monoclonal Antibodies

Immune method is difficult to obtain a monoclonal antibody (monoclonal antibody, McAb). The antibody can require forming cells and then it can be selected and cultured to obtain a monoclonal antibody specific of known in vitriol. 1975 German scholar Kohler and Milstein from British got the mouse melanoma cells by sheep red blood cells to immunize mouse splenocytes in vitriol fusion of two cells, and found that both the partially formed hybrid cells can continue in vitriol culture conditions growth and reproduction can secrete anti-SRBC antibody, this is called hybrid hybridism cell line.

3.     Genetically engineered antibodies

Since 1975, the advent of monoclonal antibody hybridism technology, monoclonal bodies in medicine is widely used in the diagnosis and treatment of diarrhea. But the vast majority of the murine monoclonal antibody, when administered in vivo to produce clinical repeated anti-mouse antibody, causing the clinical efficacy diminished or disappeared. Therefore, the clinical application of the ideal of a monoclonal antibody should be of human origin, but the human – human hybridism technology has yet to breakthrough, even if successfully developed, there are also people – human hybrid tumor passages unstable, low antibody affinity and production is not Higher problem. Office failed to present a better solution is to develop genetically engineered antibody, (genetically engineering antibody) in place of the murine monoclonal antibody for clinical use.

This is the brief introduction of the antibody’s origin and production.

Polyclonal Antibodies and Monoclonal Antibodies—-Which is More Powerful?

Polyclonal Antibodies and Monoclonal Antibodies—-Which is More Powerful?

Topic covered:

Introduction

Form of comparision

Body

Introduction

Monoclonal antibodies are produced by a specific antibody. Monoclonal antibodies can be targeted with a sigle specific epitope binding, it is just like the missile hit the target exactly. On the other hand, even if the same eoitope, the clones can generate several kinds of antibodies in bodies, then it forms a mixture of monoclonal antibodies, which is called polyclone antibodies.

Polyclonal antibodies Monoclonal antibodies
Low cost High cost
General techniques High techniques
Short time cost Long time needed for hybridomas
A large number of non-specific antibody A large number of non-specific antibody with strong specificity
Many epitopes on any antigens One epitope on one antigen

Form

Body

Polyclonal antibodies

Advantages show

 

  1. Polyclonal antibodies may help amplify low level of expression of the target protein signals, since the target protein can bind more than one antibody molecule in multiple epitopes. But this will would adversely affect the quantitative experiments, because the result will be inaccurate.
  2. Because the polyclonal antibodies can recognize multiple epitopes, it can get better results in IP / ChIP.
  3. Polyclonal antibodies can give much more space for the antigens than the monoclonal antibodies.
  4. Polyclonal antibodies can recognize the protein, which has high homology to immunogenic protein. Or it can tissue sample from a non-immunogenic target protein screened species. This is also significant to make the detection immunogen sequence to determine whether there is any crossreactivity.
  5. Polyclonal antibodies are generally preferred to detect denatured proteins.
  6. Multi-epitope generally offer more powerful detection.

 

Disadvantages show

  1. Polyclonal antibodies prone to differences between batches.
  2. Because antisera usually recognize multiple domains, polyclonal antibodies are not suitable for detecting antigens for specific domain.
  3. It will cause a large amount of non-specific antibodies, sometimes the background signal in certain applications.
  4. Multi-epitope is very important for detection of the immunogenic epitope sequence, which can be used for determining whether there is any cross-reactivity.

 

Objective fact

  1. To identify any multiple epitopes on an antigen. And the sera obtained will contain the mixture of complex heterogeneous, which is generated by the differen affinity antibodies.
  2. Polyclonal antibodies are mainly formed by IgG subclasses.
  3. Peptide immunogens is commonly used for targeting a unique epitope polyclonal antibodies, especially for highly homologous protein family.

 

Antibody preparation

  1. Low production cost
  2. Preparation techniques and skills needed are not high.
  3. Short preparation time

 

Monoclonal antibodies

Advantages show

  1. After prepared, hybridomas became a constant source of regeneration. All batches will be the same—to ensure constency and standardization eexperimental procedure and to be very helpful to the resulte.
  2. Monoclonal antibodies are usually cause the low background in the slice and cell staining. Because they are more specific detection of a target epitope. So it is less likely to cross-react with the other proteins.
  3. Because of specificity, monoclonal antibodies are very suitable for using in an anti-determination, or for detection of the antigen in cells, and the background staining is lower than polyclonal antibodies.
  4. Compared with polyclonal antibodies, monoclonal antibodies have high homogeneity. Within the same condition of experiment, the results of experiment with monoclonal antibodies has high reproducibit]lity.
  5. The specificity of monoclonal antibodies can make it bind with antigen in the mixture.

Disadvantages show

  1. It can generate a large amount of specific antibodies, but the specificity may be too strong.
  2. It is much more easier than polyclonal antibodies in lossing epitope, after chemical treated by antigens.

Objective facts

  1. It only detects one epitope on antigens.
  2. It is only formed by one antibody subtypes. When we need secondary antibody to detect antibodies, we should select the correct subtypes.

Antibody preparation

  1. High techniques are required.
  2. It can be used after preparation.
  3. Long time cost for hybridomas

These are comparation between polyclonal antibodies and monoclonal antibodies. We can not tell which one is powerful, because each one of them has its own advantages.