Q.59 HAT selection media used in monoclonal antibody production consist of
- hygromycin, ampicillin and tetracycline
- hypoxanthine, adenine and thymine
- hypoxanthine, aminopterin and thymidine
- hypoxanthine, aminopterin and thyroxine
HAT medium is essential for selecting hybridoma cells in monoclonal antibody production by eliminating unfused myeloma and spleen cells. The correct components enable precise hybridoma isolation via metabolic pathway blockade.
Correct Answer
Hypoxanthine, aminopterin, and thymidine is the right choice.
HAT Medium Mechanism
HAT selection exploits nucleotide synthesis pathways: aminopterin blocks the de novo pathway (via DHFR inhibition), forcing reliance on the salvage pathway using hypoxanthine (for purines via HGPRT) and thymidine (for pyrimidines). Hybridomas survive as they inherit HGPRT from B cells; HGPRT-deficient myelomas die, and non-replicating spleen cells perish.
Options Explained
Option Components Why Correct/Incorrect Hygromycin, ampicillin, tetracycline Antibiotics for bacterial selection ❌ Wrong; targets bacteria, not hybridomas Hypoxanthine, adenine, thymine Partial salvage precursors ❌ Wrong; adenine/thymine ineffective without aminopterin block Hypoxanthine, aminopterin, thymidine Full HAT trio ✅ Correct; enables hybridoma-only survival Hypoxanthine, aminopterin, thyroxine HAT + thyroid hormone ❌ Wrong; thyroxine irrelevant to selection
