Pharmaceutical Biotechnology and Molecular Biology
Pharmaceutical Biotechnology and Molecular Biology tests recombinant production, nucleic-acid methods, immunotechnology, and the special regulatory character of biologics. Expect questions on vectors, expression hosts, purification, and assays.
Core rules
- Recombinant DNA uses restriction enzymes, ligase, vectors, selection markers, and transformation. E. coli is fast and cheap but cannot glycosylate; CHO cells provide human-like glycosylation for antibodies.
- PCR amplifies DNA using denaturation, annealing, and extension; contamination causes false positives. RT-PCR detects RNA. ELISA quantifies proteins using capture and detection antibodies; Western blot confirms molecular size.
- Monoclonal antibodies are clone-derived and monospecific; biosimilars are not generic equivalents because manufacturing and glycosylation differ.
- Gene therapy vectors include AAV and lentivirus; CRISPR is gene editing, not a drug delivery system by itself.
Worked example
Human insulin is produced in E. coli as proinsulin, then folded and cleaved. Reasoning: E. coli lacks glycosylation but insulin does not require it. If the product were a monoclonal antibody, E. coli would be inappropriate because Fc glycosylation affects stability and effector function; CHO cells are preferred. Purification must remove host-cell proteins and endotoxin.
Traps
Calling a biosimilar a generic; ignoring endotoxin in bacterial products; assuming PCR positivity proves infectivity; forgetting that nucleic-acid therapeutics need delivery and nuclease protection.