GATE BT case studies
GATE BT · Put your knowledge to work in context.
GATE 2025 (Graduate Aptitude Test in Engineering) is a national-level examination organised by Indian Institute of Technology Roorkee on behalf of the National Coordination Board–GATE, Department of Higher Education, Ministry of Education, Government of India. It is conducted by IISc Bengaluru and seven IITs (Bombay, Delhi, Guwahati, Kanpur, Kharagpur, Madras and Roorkee). The GATE BT case studies are 5 cases and about 4,295 words.
1Fed-batch induction collapse in a high-cell-density E. coli scFv process
A 10 L fed-batch bioreactor runs E. coli BL21(DE3) carrying a pET plasmid that expresses a periplasmic scFv.
849 words, about 4 min2Choosing the polishing step for a mAb platform that misses aggregate and HCP specifications
An IgG1 monoclonal antibody is produced in CHO cells at 4.0 g/L in a 2,000 L bioreactor. The current platform is: Protein A affinity capture (yield 92%; eluate 12 g/L IgG, 5,000 ppm HCP, 8% aggregate by SEC, 800 ppb DNA), a low-pH hold at pH 3.6 for 60 min for retrovirus inactivation (no yield loss, but aggregate rises from 8% to 11%), flow-through anion exchange (yield 90%; removes 1.0 log HCP and 2 log DNA; no aggregate removal), and a final UF/DF (yield 95%).
855 words, about 4 min3Diagnosing mass-transfer limitation in an immobilised β-galactosidase packed bed
β-Galactosidase from Kluyveromyces lactis is immobilised on 500 µm chitosan beads and packed into a 2.5 cm internal diameter column with a 20 cm bed height for continuous lactose hydrolysis in whey permeate at 30 °C. At a fixed space time of 10 min, conversion varies with flow rate as follows: 38% at 0.5 mL/min, 52% at 1.0 mL/min, 61% at 2.0 mL/min, 64% at 4.0 mL/min and 65% at 8.0 mL/min.
853 words, about 4 min4A sandwich ELISA giving discordant results on high-analyte and interfering sera
A sandwich ELISA for a serum biomarker uses a capture antibody, a biotinylated detection antibody and streptavidin-HRP, calibrated from 0 to 500 ng/mL with a four-parameter logistic fit; the lower limit of quantification is 15 ng/mL and repeatability at 100 ng/mL is 8% CV. During validation, three serum samples behave oddly.
852 words, about 4 min5Recurrent Geobacillus contamination in a 500 L fermenter despite a 20-minute sterilisation hold
A 500 L stirred fermenter is sterilised in place with saturated steam. The medium is held at 121 °C for 20 min after the jacket and headspace reach temperature.
886 words, about 4 min