# DBT JRF 2020 — Question 17

Exam: DBT JRF 2020 · Section: B · Topic: Immunology · Difficulty: Medium

## Question

What is the use of Aminopterin in hybridoma production?

## Options

- **A.** to kill non-specific antibody secreting hybrids
- **B.** to kill unfused splenic cells
- **C.** to kill unfused myeloma cells
- **D.** to kill non-antibody secreting hybrids

## Answer

Option C

## Explanation

Mutations accumulate at 10 per generation; doubling time = 20 min → 3 generations per hour. Over 48 hours: Number of generations = $48 \times 3 = 144$ . Total mutations = $144 \times 10 = 1440$ . Note: this calculation assumes all generations contribute the same number of mutations (no repair or selection), and the exponential phase is maintained for the full 48 h (which is an idealised assumption, as nutrients would be exhausted in a real batch culture).

Source: https://mypyqbuddy.com/questions/what-is-the-use-of-aminopterin-in-hybridoma-6a05a8a02adafec470293229