10X Borate Saline Buffer, pH 8.3 is a borate–saline concentrate of 100 mM boric acid and 1.5 M sodium chloride in purified water. Dilution to 1X gives 10 mM boric acid and 150 mM sodium chloride at pH 8.3. The 1 L fill makes 10 L of 1X buffer.

It is commonly used to buffer amine-reactive (NHS-ester) labeling and conjugation of proteins and antibodies, since borate has no primary amines and holds the mildly alkaline pH the reaction needs. Dilute 100 mL to 1 L with purified water for 1X.