Match the item (Column I) with its corresponding use (Column II).
Column I: P. Glutamine; Q. Trypsin; R. Hypoxanthine; S. Neomycin.
Column II: 1. Detachment of adherent cells; 2. Selection of transfected mammalian cell lines; 3. Source of carbon and nitrogen in animal cell culture media; 4. A component of medium for selection of hybridoma in monoclonal antibody production.
P-3; Q-1; R-4; S-2
P-1; Q-2; R-4; S-3
P-3; Q-1; R-2; S-4
P-2; Q-3; R-1; S-4
ANSWER
The correct matching is P-3; Q-1; R-4; S-2, which is option A.
Official answer: ASource: Official answer key, GATE 2024 BT (IISc Bengaluru)
Glutamine (P) is an amino acid that animal cells use as a major source of carbon and nitrogen, and as an energy source, so it is added to culture media. P matches 3.
Trypsin (Q) is a protease that cleaves the proteins and adhesion molecules holding adherent cells to the dish and to each other, so it detaches cells for subculture. Q matches 1.
Hypoxanthine (R) is a purine precursor and a component of HAT medium (hypoxanthine, aminopterin, thymidine). Aminopterin blocks the de novo purine and thymidylate pathways, so only fused hybridoma cells that carry the B-cell HGPRT gene survive through the salvage pathway. R matches 4.
Neomycin (S) is an aminoglycoside antibiotic. The neo resistance gene (aminoglycoside phosphotransferase) lets transfected mammalian cells survive in G418 (a neomycin analogue), so neomycin resistance is used to select transfected cell lines. S matches 2.
The combination P-3, Q-1, R-4, S-2 is option A. Option B pairs trypsin with transfection selection, option C pairs hypoxanthine with transfection selection, and option D pairs glutamine with transfection selection; all three contradict the matches above.
KEY IDEA
Match each reagent to its role in animal cell culture. Glutamine is a carbon and nitrogen source, trypsin detaches adherent cells, hypoxanthine is a HAT medium component for hybridoma selection, and neomycin resistance (neo gene, G418) selects transfected mammalian cells.
WATCH OUT FOR
Pairing hypoxanthine with transfection selection, or neomycin with hybridoma selection. HAT medium selects hybridomas through the salvage pathway, while neomycin or G418 selects cells carrying the neo gene.
From the GATE 2024 BT paper. Every question of this paper · Download the full paper · All 5 Animal cell culture questions, with notes
