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Lactate accumulates as a metabolic byproduct and at concentrations >15-20 mM can inhibit cell growth and reduce productivity. Lactate management is crucial in fed-batch cultures.
Trypsin (0.05% typically) is a serine protease that digests proteins binding cells to culture vessels, allowing gentle detachment of adherent cells for subculturing.
MDCK cells are widely used for influenza virus propagation and vaccine production. They support high-titer viral replication and are approved for vaccine manufacturing.
Proper osmolarity (typically 280-320 mOsm/kg) maintains isotonic conditions, preventing cell swelling (hypotonic) or shrinkage (hypertonic), which would lead to cell damage.
As bioreactor volume increases, maintaining uniform oxygen distribution and adequate mixing becomes exponentially more difficult, requiring optimized agitation and aeration strategies.
Suspension cultures allow cells to grow at higher densities (up to 10^7-10^8 cells/mL) and are easily scalable in bioreactors, making them ideal for industrial production.
G0 (G-zero) represents the quiescent state where cells are metabolically active but not dividing. Cells can exit G1 phase and enter G0 under nutrient limitation or other stress conditions.
CHO cells are the industry standard for recombinant protein production due to their high productivity, proper protein glycosylation, and regulatory acceptance globally and in India.
Cryopreservation using liquid nitrogen or cryoprotectants like DMSO allows cells to be stored long-term while maintaining viability and genetic stability for future use.
The bicarbonate-CO₂ buffering system is essential in bioreactors to maintain physiological pH (around 7.2-7.4) as cells metabolize nutrients and produce waste products.
