Buffers and biological buffers

Each buffer works best within about one pH unit of its pKa, so the choice depends on the target pH, temperature, ionic strength and compatibility with enzymes, cells, metal ions and detection methods. Good's buffers were designed for biology with low metal binding and low UV absorbance. Buffers for cell culture, protein purification and biopharmaceutical production need higher grades with endotoxin, DNase, RNase and protease testing.

Ask for assay, pH of a stated solution, UV absorbance, heavy metals, water, and for bioprocess grades endotoxin and bioburden limits, animal origin statements and multi-compendial compliance. Large biopharmaceutical users also need change notification agreements and lot-to-lot consistency. pH standard solutions should be traceable to national standards.