Biotechnology

🔭 Genetic Engineering

Genetic engineering inserts a gene from one species into the genome of another organism (transgenic organism) to produce a desired protein.

• Step 1: Identify and isolate the desired gene (e.g. human insulin gene)
• Step 2: Cut the gene out using restriction endonucleases (cut at specific sequences, leaving sticky ends)
• Step 3: Cut a bacterial plasmid with the same restriction enzyme
• Step 4: Insert gene into plasmid using DNA ligase → recombinant plasmid
• Step 5: Insert plasmid into host bacterium (transformation)
• Step 6: Bacteria multiply, expressing the gene and producing the desired protein

🔭 PCR, Cloning, and Stem Cells

• PCR (Polymerase Chain Reaction) — amplifies specific DNA sequences: Denature (95°C) → Anneal primers (55°C) → Extend (Taq polymerase, 72°C)
• Gel electrophoresis — separates DNA by size; used in DNA profiling (forensics, paternity)
• Stem cells — undifferentiated cells that can become many cell types; embryonic (pluripotent) or adult (multipotent)
• Therapeutic cloning — creates patient-matched stem cells for tissue repair (NOT reproductive cloning)