Buffer solutions, particularly basic pH buffers, tend to act as a media for fungus and bacteria growth. This buffer preservative contains a highly effective anti-fungal, anti-bacterial agent to provide long-term protection for buffer solutions and does not affect pH value. The preservative is available in two forms: preservative only, colorless (Catalog No. B0175 or preservative with indicator (Catalog No. B0176). If the preservative with indicator is used, the buffer will be tinted green for neutral solutions, orange-red for acid solutions and blue for basic solutions. Please specify whether you want clear, non-indicating preservative or the preservative with indicator. Three drops of preservative provides ample protection and, in the case of the indicating preservative, a distinct tint for 100 mL of buffer solution.