HEPES-buffered saline (16-3)

21 mM HEPES

0.7 mM Na₂HPO₄

6 mM dextrose

5 mM KCl

137 mM NaCl

Adjust the pH of the solution to 7.10. Sterilize the solution by filtration and store frozen in 25-50-ml aliquots. Thaw a fresh aliquot before each transfection and check the pH of a small volume. Readjust pH is necessary to 7.10.