Discovery

 Monoclonal antibodies are produced from a single clone of B cells and are highly specific to a single epitope on an antigen. They are known for their high specificity and consistency, making them ideal for diagnostic assays. 

Process:

1. Antigen Preparation: Selection and preparation of the target antigen.
2. Immunization: Immunizing mice or other host animals with the prepared antigen.
3. Cell Fusion: Fusing spleen cells from the immunized animal with myeloma cells to create hybridoma cells.
4. Screening: Screening the hybridoma cells for those producing the desired antibody.
5. Cloning: Cloning positive hybridoma cells to ensure monoclonality.
6. Production: Culturing the cloned cells to produce monoclonal antibodies.
7. Purification: Purifying the antibodies from the culture supernatant.
8. Characterization: Characterizing the antibodies for specificity, affinity, and other relevant properties.

 Polyclonal antibodies are produced by different B cell clones in response to an antigen, recognizing multiple epitopes. They offer higher sensitivity and broader detection capabilities for various applications. 

Process:

1. Antigen Preparation: Selection and preparation of the target antigen.
2. Immunization: Immunizing host animals (e.g., rabbits, goats) with the prepared antigen.
3. Booster Immunizations: Administering booster shots to enhance antibody production.
4. Serum Collection: Collecting blood from the immunized animals.
5. Antibody Extraction: Extracting antibodies from the serum.
6. Purification: Purifying the antibodies to remove non-specific proteins.
7. Characterization: Characterizing the antibodies for specificity, affinity, and other relevant properties.

 Recombinant antibodies are generated through genetic engineering, allowing for precise control over the antibody sequence and structure. These antibodies can be designed for improved specificity and stability. 

Process:

1. Gene Synthesis: Synthesizing the genes encoding the antibody variable regions.
2. Cloning: Inserting the antibody genes into expression vectors.
3. Expression: Transfecting suitable host cells (e.g., CHO cells) with the expression vectors.
4. Screening: Screening for high-expressing clones.
5. Production: Culturing the selected clones to produce recombinant antibodies.
6. Purification: Purifying the antibodies from the culture supernatant.
7. Characterization: Characterizing the antibodies for specificity, affinity, and other relevant properties.

Antibody pairs are essential for sandwich assays such as ELISA and immunochromatographic tests, where one antibody captures the antigen and the other detects it. These pairs must be carefully selected and validated for optimal performance.

Process:

1. Antigen Preparation: Selection and preparation of the target antigen.
2. Antibody Generation: Developing monoclonal or polyclonal antibodies against the antigen.
3. Pair Screening: Screening antibody pairs for their performance in sandwich assays.
4. Optimization: Optimizing the selected pairs for maximum sensitivity and specificity.
5. Validation: Validating the antibody pairs in relevant diagnostic assays.
6. Production: Producing and purifying the validated antibody pairs.
7. Characterization: Characterizing the antibody pairs for performance parameters such as sensitivity, specificity, and stability.

Antibody humanization involves modifying non-human antibodies (e.g., mouse antibodies) to resemble human antibodies more closely. This process reduces the immunogenicity of the antibodies when used in human therapeutic applications.

Process:

1. Sequence Analysis: Analyzing the sequence of the original non-human antibody.
2. Human Framework Selection: Selecting suitable human antibody frameworks.
3. Grafting CDRs: Grafting the complementarity-determining regions (CDRs) from the non-human antibody onto the human frameworks.
4. Back-Mutation: Introducing critical back-mutations to restore the original binding affinity.
5. Expression: Cloning the humanized antibody genes into expression vectors and transfecting them into host cells.
6. Screening: Screening for clones that express the humanized antibody.
7. Production: Culturing the selected clones to produce the humanized antibodies.
8. Purification: Purifying the antibodies from the culture supernatant.
9. Characterization: Characterizing the antibodies for specificity, affinity, immunogenicity, and other relevant properties.

Antibody fragments, such as single-chain variable fragments (scFv) and single-domain antibodies (VHH), offer several advantages, including smaller size and better tissue penetration. They are useful in both diagnostic and therapeutic applications.

Process:

1. Antigen Preparation: Selection and preparation of the target antigen.
2. Phage Display Library Construction: Constructing a phage display library expressing antibody fragments.
3. Library Screening: Screening the phage display library to identify antibody fragments that bind to the target antigen.
4. Clone Selection: Selecting positive clones expressing high-affinity antibody fragments.
5. Expression: Cloning the selected antibody fragment genes into expression vectors and transfecting them into host cells.
6. Production: Culturing the host cells to produce antibody fragments.
7. Purification: Purifying the antibody fragments from the culture supernatant.
8. Characterization: Characterizing the antibody fragments for specificity, affinity, stability, and other relevant properties.