UNIT 5: Special Secondary Metabolites and Hybridoma Technology

Exam Focus: **Hybridoma Technology** for Monoclonal Antibody (mAb) production is one of the most important concepts. Be prepared to describe the role of the B-cell, the myeloma cell, PEG, and the HAT medium (from Unit 4) in detail. Also, know the medical application of the key metabolites (TPA, Interferon).

Table of Contents

  1. Special Secondary Metabolites
  2. Hybridoma Technology and Monoclonal Antibodies

1. Special Secondary Metabolites

These are therapeutic proteins and hormones produced in large quantities using animal cell culture systems.

Insulin

A peptide hormone, recombinantly produced, used in the treatment of Diabetes Mellitus.

Growth Hormone (Somatotropin)

A protein hormone that stimulates growth; recombinantly produced for the treatment of growth deficiencies.

Interferon (IFN)

A cytokine produced by cells in response to viruses, used therapeutically for treating viral diseases and certain cancers.

TPA (Tissue Plasminogen Activator)

An enzyme used as a "clot-buster" in medicine to dissolve unwanted blood clots, for example, during stroke or heart attack treatment.

Factor VIII

A critical blood clotting protein produced recombinantly for the treatment of Haemophilia A.

2. Hybridoma Technology and Monoclonal Antibodies

Monoclonal and Polyclonal Antibodies

Feature Monoclonal Antibodies (mAbs) Polyclonal Antibodies
**Specificity** Highly specific; recognizes only **one epitope** on an antigen. Recognizes **multiple epitopes** on an antigen.
**Source** Single clone of hybridoma cells. Serum from an immunized animal (many different B-cell clones).
**Supply** Infinite, uniform supply. Limited supply, batch-to-batch variation.

Production of Monoclonal Antibodies (Hybridoma Technology)

Hybridoma technology is the process of generating **hybridoma cells** (hybrid B-cells) that can produce a single, specific antibody (monoclonal) indefinitely.

  1. **Fusion:** Antibody-producing **B-lymphocytes** (mortal) are fused with **immortal myeloma cells** (cancer cells) using a fusion agent like PEG.
  2. **Selection:** The fused hybridomas are selected using HAT medium (see Unit 4).
  3. **Cloning:** Surviving hybridomas are screened and cloned to ensure large-scale production of the desired monoclonal antibody.

Application of Monoclonal Antibodies

mAbs are used extensively in biomedical fields: