Antibodies are the number one immune cells that fight against infection and diseases. However, beyond their natural usage, biochemistry has devised several ways in which these antibodies can be modified and used to detect various diseases in laboratories and determine the protein structure of other proteins.
What Goes into Making Recombinant Antibodies
Antibodies can be classified into two types: monoclonal and polyclonal. Monoclonal antibodies have specificity for a particular antigen (target of antibodies), but polyclonal ones are not specific to any antigen. Recombinant ones are monoclonal, and here are the key steps involved in their production.
Recombinant antibody production involves the use of recombinant DNA technology to produce an antibody. In this blog post, you will learn all about the process of recombinant antibody production, its utilities, and its advantages.
Step One: Choosing the Right Antigen
The target an antibody binds to needs to be specific to it to work well. When you are designing an antibody, you have to decide which part of the antigen it is best suited for. The shapes of proteins, whether antigens or antibodies have definite 3D shapes that will critically determine if the antibody is going to bind with its antigen tightly. Hence, in order to select the most appropriate sequence for binding, you may have to study the 3D structure of the proteins and then only choose a binding site correctly.
Step Two: Creating the Recombined DNA Sequence
Depending on the properties that you want the antibody to express, you have to create a suitable DNA sequence. Typically, in an organism, DNA encodes for a protein, so creating the correct DNA sequence is key to creating a functional protein, in this case, a functional antibody. Depending on the types of proteins that you wish to express, you may take a bioinformatics approach that uses existing databases to search for the sequence.
Step Three: Expression Plasmid Construction
Plasmids are small pieces of circular DNA that have properties that make them very useful for laboratory work.
Restriction endonucleases are often used in research to cut and paste DNA sequences in a plasmid. For example, if you wish the recombinant protein to bind an antibody and also produce a fluorescent dye, then you must cut and paste the individual sequences encoding for antibody recognition and fluorescent protein expression. Plasmids can replicate very fast once they are inserted in a host cell, which could be a bacteria.
Step Four: Transfection of Plasmids
Inserting the plasmid in the bacteria so that it can multiply fast and produce sufficient quantities of the required antibody requires transfection. The bacteria cell or any host cell is made compatible so that it readily takes up the recombinant plasmid DNA. Usually, salt washes are used to improve the efficiency of the transaction process.
Step Five: Purification Process
The final step in creating the antibody is the purification process to purify the antibody of interest.
Uses of Recombinant Antibodies
As has been said earlier, recombinant antibodies have several uses, and some of them will be discussed here.
Use for Diagnosis of Diseases
One common application of recombinant antibodies is the ELISA test, which is used to detect diseases like COVID. Here, the sample from the diseased person is embedded in a matrix.
The matrix is then flooded with the recombinant antibody that can specifically bind the antigen of the disease being tested. The other end of the recombinant protein is coded for a dye, so if enough antigen exists, the antibody sticks in adequate numbers, and the intensity of the dye will indicate the disease.
Use in Research
Recombinant antibodies are widely used in research work. One such application is known as blotting, which detects the presence of a particular protein in a sample. Likewise, these antibodies can be used to detect the positional information of a protein in a tissue, and this is known as immunohistochemistry.
Advantages of Using Recombinant Antibodies
There are a lot of advantages associated with creating recombinant antibodies. Some of them are discussed in detail below:
Makes No Use of Animals
The usual technique of producing polyclonal antibodies involves injecting an animal like a hamster or a rabbit with an antigen. After this injection, the animal's body reacts to produce antibodies. The serum of the animal is collected to extract the antibody of interest.
For monoclonal antibodies, cells are used from an animal's spleen to eventually create cells that can multiply as fast as cancer cells. In both the techniques mentioned above, animals are involved in one way or the other. However, producing recombinant antibodies makes no use of animals, and this prevents cruelty towards them.
Quick Production
Production of recombinant antibodies is a quick process, and scaling up the production of such antibodies can happen quite quickly.
Stability of the Antibodies
Recombinant antibodies are quite stable, and the stability that is preserving the structure of a protein is critical for it to function properly. Proteins get damaged quite easily if they are exposed to very high or very low temperatures or if they are exposed to enzymes.
Even recombinant antibodies can get damaged by extremes of temperature; however, they are more stable than other proteins that are used in the laboratory.
Final Words
Creating antibodies, be it Abcam monoclonal antibodies or recombinant ones, requires dedicated research and effort. Nonetheless, the time and effort in making these antibodies are worth it as they are immensely useful in disease detection, research, blood typing, etc. Moreover, creating them causes no harm to animals; creating them consumes less time and involves less expenditure when compared to creating antibodies by other techniques.
