HBSS for BAP (2X)

50 mM HEPES

1.5 mM Na₂HPO₄

280 mM NaCl

• 1. Dissolve the solid forms of each reagent in 400 mL of ultrapure water, using a sterile glass beaker.

• 2. Adjust the pH to 7.00 (using NaOH or HCl as needed), and then bring the volume up to 500 mL with additional ultrapure water.

• 3. Adjust pH again and sterilize by filtration in a laminar flow hood (0.2-μm-pore filter bottles; Corning 430769).

• 4. Test the batch for transfection efficiency using a reporter plasmid (e.g., expressing enhanced green fluorescent protein [EGFP]).

  If the transfection efficiency is adequate, this reagent can be stored for many months at 4°C for repeated use.