Detailed Notes -2 -CHAPTER 10 BIOTECHNOLOGY AND ITS APPLICATIONS

10.2.3 Molecular Diagnosis

1. Importance of Early Diagnosis:

   • Early diagnosis is crucial for effective treatment of diseases.
   • Conventional methods like serum and urine analysis may not detect diseases at early stages.

2. Molecular Diagnostic Techniques:

   • Recombinant DNA Technology: Used in molecular diagnostics for various purposes, including gene amplification and analysis.
   • Polymerase Chain Reaction (PCR):
     • Purpose: Used to detect very low amounts of DNA or RNA, especially pathogens like bacteria or viruses, before disease symptoms appear.
     • Mechanism: PCR amplifies specific DNA sequences through repeated cycles of denaturation, annealing, and extension, resulting in a detectable amount of DNA for analysis.
     • Clinical Applications: Used for early HIV detection in AIDS patients, detecting gene mutations in cancer patients, and identifying genetic disorders.

3. Principle of PCR for Detecting Low Amounts of DNA:

   • PCR amplifies small amounts of DNA by repeatedly heating and cooling the reaction mixture.
   • Denaturation separates the DNA strands, annealing allows primers to bind to specific DNA sequences, and extension synthesizes new DNA strands from the primers.
   • This process amplifies the target DNA exponentially, making it detectable even at low initial concentrations.

4. Mutation Detection Using Hybridization and Autoradiography:

   • Single-stranded DNA or RNA probes tagged with radioactive molecules are used to hybridize with complementary DNA sequences in cell clones.
   • Mutated genes do not hybridize with the probe and therefore do not appear on autoradiography, indicating the presence of mutations.

5. Enzyme-Linked Immuno-Sorbent Assay (ELISA):

   • Based on antigen-antibody interactions.
   • Detection of infection: Antigens (proteins, glycoproteins, etc.) from pathogens or antibodies produced against them can be detected using ELISA.

10.3 TRANSGENIC ANIMALS

1. Normal Physiology and Development:

   • Purpose: Transgenic animals are designed to study gene regulation and their effects on normal body functions and development.
   • Example: Studying insulin-like growth factors by introducing genes from other species to understand biological roles and factors affecting growth.

2. Study of Disease:

   • Purpose: Transgenic animals serve as models to understand how genes contribute to disease development.
   • Applications: Used to study diseases like cancer, cystic fibrosis, rheumatoid arthritis, Alzheimer’s, aiding in the investigation of new treatments.

3. Biological Products:

   • Purpose: Create transgenic animals that produce valuable biological products.
   • Example: Introduction of genes coding for human proteins like α-1-antitrypsin used to treat emphysema, or producing human protein-enriched milk (like Rosie the transgenic cow) for medical purposes.

4. Vaccine Safety:

   • Purpose: Develop transgenic animals for testing vaccine safety before human trials.
   • Example: Transgenic mice used to test the safety of the polio vaccine, potentially replacing the need for testing on monkeys and accelerating vaccine development.

5. Chemical Safety Testing (Toxicity Testing):

   • Purpose: Evaluate toxicity and safety of chemicals using transgenic animals.
   • Procedure: Transgenic animals are engineered to be more sensitive to toxic substances, allowing quicker and more accurate toxicity testing than non-transgenic animals.

10.4 ETHICAL ISSUES

1. Need for Ethical Standards:

   • Manipulation of living organisms requires ethical standards to evaluate activities that may benefit or harm organisms.
   • Ethical considerations are crucial to assess the morality of human actions involving living organisms.

2. Biological Significance and Ecosystem Impact:

   • Genetic modification of organisms can lead to unpredictable outcomes when introduced into the ecosystem.
   • Consideration of biological impacts is essential to ensure environmental sustainability and prevent unintended consequences.

3. Government Regulations and Committees:

   • The Indian Government has established organizations like GEAC (Genetic Engineering Approval Committee) to regulate GM research and assess safety in introducing GM organisms.
   • These committees make decisions regarding the validity of GM research and the safety of GM organisms for public services like food and medicine.

4. Issues with Patents and Biopiracy:

   • Patent problems arise when companies patent products and technologies derived from genetic materials, plants, and biological resources traditionally used by farmers and indigenous people.
   • Biopiracy refers to the unauthorized use of bio-resources by multinational companies without proper compensation or authorization.

5. Examples of Patents and Biopiracy:

   • Basmati rice patent: An American company patented a “new” variety of Basmati rice derived from Indian varieties, leading to restrictions on traditional Basmati growers.
   • Traditional herbal medicines: Attempts to patent uses, products, and processes based on Indian traditional knowledge like turmeric and neem.

6. Legislative Responses:

   • The Indian Parliament has taken steps to address these issues through amendments to the Indian Patents Bill.
   • Measures include patent terms, emergency provisions, and initiatives for research and development, aiming to protect traditional knowledge and prevent unauthorized exploitation of bio-resources.