Govt. Exams
Entrance Exams
Cell culture is crucial for pharmaceutical companies in India to conduct in vitro drug screening and toxicity testing, reducing reliance on animal testing per regulatory guidelines.
5% CO₂ is standard in mammalian cell culture incubators. It helps maintain pH (7.2-7.4) by forming a carbonate buffer system with bicarbonate in the medium.
Bacterial contamination typically causes increased acidity, turbidity, and odor but suppresses mammalian cell growth due to competition and toxins. Mammalian cell division rate would decrease, not increase.
Contact inhibition is a regulatory mechanism where normal cells cease dividing once they form a complete monolayer and contact neighboring cells, unlike transformed cells.
Serum-free media have defined, known compositions without variable components of serum, providing better reproducibility in research and reducing lot-to-lot variability.
Trypan blue is a vital dye that enters dead/damaged cells but is excluded by viable cells with intact membranes, allowing quick assessment of post-thaw viability.
The Hayflick limit describes the maximum replicative potential of normal human cells (~50-70 divisions) due to telomere shortening, after which cells enter senescence.
Heating damages cells. Proper cryopreservation uses liquid nitrogen (-196°C) with cryoprotectants like DMSO or glycerol to prevent ice crystal formation that damages cell membranes.
Cell doubling time indicates the rate at which cells divide and reflects their growth kinetics and overall health. It's calculated from exponential growth phase data.
Fetal Bovine Serum (FBS) contains essential growth factors, hormones, and attachment factors that promote cell growth and proliferation in culture.
