Govt. Exams
Entrance Exams
Microcarriers (Cytodex, Microcarrier, etc.) provide surface area for anchorage-dependent cells in suspension bioreactors, combining advantages of both culture systems.
Suspension cultures (used for hybridomas, CHO cells) allow cells to grow freely, achieve higher densities, and scale more easily than adherent cultures which require surface attachment.
While CHO cells are used for complex proteins, E. coli is the primary system for insulin production in Indian industries due to cost-effectiveness and regulatory acceptance. However, CHO is also important for other biologics.
Perfusion culture continuously removes metabolic waste and supplies fresh medium while retaining cells, resulting in higher cell densities and productivity compared to batch culture.
5% CO2 maintains pH through bicarbonate buffering, 5% O2 provides aerobic respiration, and N2 balances the gas mixture. This mimics physiological conditions.
Passage number indicates how many times cells have been subcultured/transferred. Higher passage numbers may result in senescence and altered cell characteristics.
DMSO and glycerol are cryoprotectants that prevent ice crystal formation and cell damage. Cells are stored at -196°C in liquid nitrogen. Rapid thawing is recommended.
Animal serum is costly, batch-to-batch variability is high, regulatory concerns exist, and it complicates downstream processing. Industries are shifting to serum-free media.
Dilution rate (D) = flow rate (F)/culture volume (V). In chemostat culture, growth rate equals dilution rate at steady state.
Stirred-tank bioreactors with integrated aeration and agitation systems are ideal for industrial-scale mammalian cell culture, offering better control and scalability.
