Culture Medium for Cell Lines

Culture media are crucial for maintaining and propagating cell lines in vitro. They provide essential nutrients, growth factors, and hormones necessary for cell growth and division. The composition of culture media can significantly impact cell physiology, morphology, and behavior.

Key Components of Culture Medium

• Basal Medium: This provides the fundamental nutrients required by cells. Common basal media include DMEM (Dulbecco's Modified Eagle Medium), RPMI-1640, and MEM (Minimum Essential Medium).
• Amino Acids: Essential for protein synthesis, amino acids like L-glutamine are vital components. L-glutamine serves as a carbon and nitrogen source for cells.
• Vitamins: Necessary for metabolic functions and cell viability. For example, B-vitamins play critical roles in energy metabolism.
• Salts: Maintain osmotic balance and provide essential ions for cell function. Common salts include sodium chloride (NaCl), potassium chloride (KCl), and calcium chloride (CaCl2).
• Glucose: An energy source that supports cellular respiration and ATP production. Glucose concentration in the medium can affect cell growth rates and metabolic activities.
• Serum: Typically fetal bovine serum (FBS), it supplies growth factors, hormones, and attachment factors. However, serum can introduce variability, leading to the development of serum-free media for more consistent results.
• Buffering Agents: Maintain pH stability. Bicarbonate (HCO3-) and HEPES are commonly used buffers to keep the pH around 7.2-7.4, optimal for most mammalian cell lines.
• Antibiotics: Often added to prevent bacterial contamination. Penicillin and streptomycin are frequently used antibiotics in cell culture.

Preparation and Sterilization

• Preparation: Measure and mix the basal medium components with deionized water. Adjust the pH, usually with NaOH or HCl, to the desired level.
• Sterilization: Filter sterilization is preferred to maintain the integrity of heat-sensitive components. Typically, a 0.22-micron filter is used to remove contaminants.

Usage and Storage

• Usage: Media should be pre-warmed to 37°C before use to avoid shocking the cells. Continuous monitoring of pH and contamination is essential during cell culture.
• Storage: Store prepared media at 4°C. Avoid repeated freeze-thaw cycles as they can degrade sensitive components