Nonidet P40 Substitute Troubleshooting

Product No. NONP40-RO


Difficulties with protein solubilization

Nonidet P40 is a detergent with a very low Critical Micell Concentration (CMC) (0.25 mM). The CMC of nonionic detergents increases with rising temperature. Therefore solubility should be better at higher temperatures. Salt concentration does not effect the solubility of nonionic detergents. Nonidet P40 will not solubilize all proteins due to the low CMC. It can be used for partial solubilization as a first step in isolation of a protein-fraction. For solubilization of all proteins in one step, use a detergent with a higher CMC, such as n-Octylglucoside.

For best results, add the detergent to the sample, vortexing or pipetting up and down, and then centrifuging shortly to remove unsolubilized components. The supernatant will contain all protein solubilized in the detergent. For subsequent protein determination dilutions should be done in the detergent′s working concentration. The CMC change will otherwise result in deposits and precipitates. Please refer to the package insert of this product for more details.


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