Balanced salt solutions and powders used for molecular, protein, nucleic acid, and cell biology applications including cell culture, electrophoresis, ELISA, and chromatography processes; available in a variety of formulations and grades.

Buffer solutions serve to keep pH (acidity or alkalinity) nearly constant in a variety of chemical and biological applications. For example, a bicarbonate buffer helps maintain the pH of blood, a buffered saline maintains cellular contents at a consistent pH level, and buffers help maintain a narrow pH range for enzymes to function correctly.

Most biological samples used in research are kept at a pH of about 7.4. Common biological buffers used for tissue culture include Dulbeccos phosphate buffered saline (PBS), Tris base, HEPES, MOPS, PIPES, and other formulations developed for specific cell lines or applications. Most buffers used in cell culture are also DNase-, RNase-, and protease-free.

The choice of buffer for a particular biological reaction or site depends on several factors:

• Temperature
• Desired or target pH
• Buffer toxicity (to the system)
• Buffer interactions with other system components