Buffer Solutions & Protocols: A Guide for Labs

Buffers refers to solutions that resist changes in pH or acidity when small quantities of an acid or an alkaline compound are added to them. Buffer protocols are technical procedures used in chemical and biological laboratories for scientific research. Protocols for buffers include citrate buffer antigen retrieval, phosphate buffered saline and polymerase chain reaction buffer.

Citrate Buffer Antigen Retrieval

• Sodium citrate or citric acid are used in this protocol as buffers during laboratory tests to detect certain proteins called antigens. Technicians pre-heat a water bath, place a staining dish containing sodium citrate or citrate into the bath and wait until the temperature reaches 212 degrees Fahrenheit. Later, they immerse slides with tissue samples in the staining dish, incubating for 40 minutes. Slides are then rinsed with PBS-Tween detergent. Finally, slides are incubated with antigens for at least an hour at room temperature, reports Rocky Tuan in "Developmental Biology Protocols."

Phosphate Buffered Saline (PBS)

• Phosphate buffered saline ( PBS) is a buffer solution often used in biological research. The PBS protocol consists of mixing disodium phosphate (Na2HPO4), monosodium phosphate (NaH2PO4), sodium chloride and distilled water. The pH of this solution should reach a value of 7.4, slightly above neutral.

Polymerase Chain Reaction

• Polymerase chain reaction (PCR) buffer protocol uses the chemical compounds potassium chloride (KCl), tris-hydroxymethyl-aminomethane, commonly referred as Tris and magnesium chloride (MgCl2). This protocol is used in the analysis of enzymes, such as polymerase. PCR buffer solutions are available commercially in different concentrations, according to the Laboratory for Microbial Ecology of the University of Toledo.