Special staining protocols are often dependent on the use of acids, bases, and buffers for favorable staining outcomes. The pH of a staining solution is a measure of its acidity (the balance of hydrogen ions (H+) and hydroxyl ions (OH).
On a pH scale of 1-14
1 - 6.9 is
Acidic (More hydrogen than hydroxyl ions)
7 - 7.4 is
Neutral (Equal hydrogen and hydroxyl ions)
7.5 - 14 is
Basic (More hydroxyl than hydrogen ions)
Buffers are substances that are often added to staining solutions to prevent fluctuations in pH.