BioGnost’s Buffer solution pH 6.4 contains sodium and potassium phosphates that enable the solution to be buffered at pH 6.4. The buffer solution’s molality is 6 nM and it is recommended for use in practical hematology during blood smears staining procedures. In that case the buffer solution is essential for preparation of diluted Giemsa/May-Gruenwald/Wright/Leishman solutions and for rinsing stained samples without causing destaining of stained cells. Buffer solutions are solutions of weak acids and theirs salts or weak bases and their salts. They enable maintaining approximately constant pH value by adding a certain amount of strong acids or bases.