BioTech_ WACE

What is recombinant DNA technology used for in medicine?

Recombinant DNA technology allows genes from one organism to be inserted into another to produce medically useful substances such as human insulin, human growth hormone, clotting factors, and vaccines

How is human insulin produced using recombinant DNA technology?

• The human insulin gene is isolated using restriction enzymes
• A plasmid is cut using the same restriction enzyme to create matching sticky ends
• The insulin gene is inserted into the plasmid using DNA ligase
• The recombinant plasmid is inserted into bacterial cells (transformation)
• Bacteria reproduce rapidly and express the insulin protein, which is purified for medical use

What are the steps in creating recombinant DNA for medical use?

• Identify and isolate the desired gene from human DNA
• Cut both the gene and plasmid vector with the same restriction enzyme
• Join the gene and plasmid using DNA ligase
• Introduce the recombinant plasmid into bacterial host cells
• Allow the bacteria to multiply and express the target protein
• Harvest and purify the protein for medical use

What are examples of medical products made using recombinant DNA technology?

Insulin for diabetes treatment, human growth hormone for growth disorders, clotting factor VIII for haemophilia, and hepatitis B vaccines

What are the advantages of recombinant DNA technology in medicine?

• Allows large-scale, consistent, and safe production of human proteins
• Reduces risk of allergic or immune reactions compared to animal-derived products
• Enables rapid production and easy genetic modification for improved efficiency

What are the disadvantages of recombinant DNA technology in medicine?

• High research and production costs
• Risk of contamination or mutation in microorganisms
• Ethical concerns surrounding use of genetically modified organisms

What is gene therapy?

Gene therapy is the insertion, alteration, or replacement of faulty genes in human cells to treat or prevent genetic disorders

What are the two main types of gene therapy?

Somatic gene therapy targets non-reproductive cells and is not inherited, while germline gene therapy targets gametes or embryos and is heritable but banned in humans due to ethical concerns

How is gene therapy carried out?

• Identify the defective gene responsible for a disorder
• Design a healthy copy of the gene
• Insert the gene into a vector such as a virus, liposome, or nanoparticle
• Deliver the vector into the patient’s target cells
• The new gene is expressed to produce the correct protein, restoring normal function

What are examples of diseases targeted by gene therapy?

Cystic fibrosis, severe combined immunodeficiency (SCID), muscular dystrophy, and certain cancers

What are advantages of gene therapy?

• Addresses the underlying genetic cause of diseases
• Potentially provides permanent or long-term cures
• Reduces need for ongoing treatments or medications

What are disadvantages of gene therapy?

• Possibility of immune reaction or viral infection
• Risk of inserting the gene into the wrong site (insertional mutagenesis)
• Very high costs and ongoing ethical debate over human genetic modification

What is CRISPR-Cas9 and how is it used in medicine?

• CRISPR-Cas9 uses a guide RNA to locate a specific DNA sequence in the genome
• The Cas9 enzyme cuts the DNA at that exact site
• Scientists can then delete, replace, or insert genes to correct mutations or modify function
• Used for gene correction and experimental treatment of genetic diseases

What are examples of medical uses of CRISPR-Cas9?

Correcting mutations in diseases such as sickle cell anaemia, cystic fibrosis, and muscular dystrophy, and engineering immune cells to fight cancer

What are advantages of CRISPR-Cas9 in medicine?

• Extremely precise and programmable
• Cheaper and faster than older methods of gene editing
• Potential for permanent cures with single treatments

What are disadvantages or concerns of CRISPR-Cas9 in medicine?

• Risk of off-target DNA cuts or unintended mutations
• Ethical concerns about human embryo editing
• Potential misuse for non-medical “enhancement” purposes

What is the polymerase chain reaction (PCR) used for in medicine?

PCR amplifies DNA to produce millions of copies from a small sample, used for disease diagnosis, genetic testing, and detecting infections

What are the steps in PCR?

• Denaturation – DNA is heated to 95°C to separate strands
• Annealing – primers attach to target DNA sequences at ~55°C
• Extension – Taq polymerase builds new DNA strands at 72°C
• The cycle repeats multiple times, doubling DNA each cycle

What are examples of PCR use in medical testing?

Detection of viral infections (HIV, COVID-19), identification of genetic disorders (cystic fibrosis), and matching donor DNA for transplants

What are advantages of PCR in medical diagnostics?

• Highly sensitive, detecting even minute DNA samples
• Rapid results for early diagnosis
• Allows analysis of genetic material before symptom onset

What are disadvantages of PCR in medical use?

• Requires precise temperature control and equipment
• Risk of contamination producing false positives
• Only amplifies specific DNA fragments

What is gel electrophoresis used for in medical biotechnology?

• DNA samples are placed in a gel
• Electric current separates fragments by size (smaller fragments travel faster)
• Used to analyse DNA for genetic testing or confirm PCR results

What is DNA profiling used for in medicine?

DNA profiling compares genetic markers to identify inherited diseases, confirm donor compatibility, or trace hereditary conditions

What are advantages of DNA profiling in medicine?

• Detects carrier status for genetic disorders
• Assists with early diagnosis and personalised treatment plans
• Enables accurate tissue and organ donor matching

What are disadvantages or ethical concerns of DNA profiling in medicine?

• Potential breaches of genetic privacy
• Risk of discrimination by employers or insurers
• Possibility of data misuse or hacking