Phosphate Buffered Saline, pH 7.4

PBS is used for routine immunohistochemical testing and as a general purpose solution for washing cells in various haematological and molecular biology procedures. All media used in tissue culture have a basis of a synthetic mixture of inorganic salts known as a physiological or balanced salt solution (BSS). All the physiological salt solutions have been derived from the salt solution originally described by Sydney Ringer (1885). The first balanced salt solution to be developed specifically for supporting the metabolism of mammalian cells was Tyrode's solution. Since then many modifications have been done to obtain better buffering salt solutions and to prevent calcium precipitation. Phosphate Buffered Saline pH 7.4 is most commonly used for tissue disaggregation and monolayer dispersal since presence of calcium and magnesium ions may hinder the trypsin activity.