Table II.

Osmolarity of Buffers Used in ATP Efflux Assay

Buffer base		Predominant anion composition		Osmolarity
				mOsmol
HPBR		140 mM NaCl		303 ± 5
		140 mM Na-gluconate		295 ± 3
		140 mM NaBr		293 ± 4
SOS		100 mM NaCl		205 ± 2
		100 mM Na-gluconate		204 ± 2
		100 mM NaBr		204 ± 3

The osmolarity of these solutions was determined on a Multi-Osmette Model 2430 Automatic Osmometer (Precision Systems, Natick, MA).