Role of a balanced salt solution in cell culture is multifaceted and can be divided into four principal functions:

• Serves as an irrigating, transporting and diluting fluid while maintaining intra- and extracellular osmotic balance
• Provides cells with water and certain bulk inorganic ions essential for normal cell metabolism
• Combined with a carbohydrate, such as glucose, provides the principal energy source for cell metabolism
• Provides a buffering system to maintain the medium within the physiological pH range (7.2 to 7.6)

Lymphocytes are isolated by layering diluted, heparinized blood over a solution of sodium metrizoate that contains a polysaccharide. This polysaccharide aggregates the erythrocytes so that they can be sedimented by low centrifugation. The less dense lymphocytes remain as a clearly defined band at the plasma Lymphosep interface.

Dissolve one tablet in 100 ml distilled water. Autoclave for 10 minutes at 115 °C. The pH will be in the range 7.3 to 7.5. The buffer can be adjusted as desired with dilute HCl or NaOH.