A pH indicator is premixed with the Gel/PCR binding buffer to ensure
optimal pH, facilitate DNA binding and allow for easy observation of
undissolved agarose gel. If pH exceeds the optimal level (>7.5), the
color of the solution will appear purple instead of yellow. 3M Sodium
Acetate (pH5.0), which is included with the kit, can then be added to the
solution to adjust pH and return the color to yellow.