Sara Lahsaee Little, Victoria A Miller Proteoform Scientific Inc. Halifax, NS Canada
Sodium dodecyl sulphate is a commonly used detergent for protein extraction, particularly for membrane proteins. Adequate removal of the anionic detergent, to levels below 100 ppm, or preferably lower, has been a source of frustration for mass spectrometry users for some time. Precipitation has been used in the past but has a reputation for inconsistent performance. Other methods have been suggested including dialysis and buffer exchange, such as FASP (centrifugal-aided), as well as ion exchange, electrophoresis, and detergent affinity matrices. Many of these strategies have drawbacks including loss of proteins, incomplete detergent removal, and a high cost per use. Standardization of the precipitation process can result in the minimization of sample loss and improvement in reproducibility.