Critical micelle concentration (CMC)
From OpenWetWare
Critical micelle concentration (CMC) is defined as the concentration of detergents above which micelles are spontaneously formed. The CMC is important in biology because at concentrations above it the detergents form complexes with lipophilic proteins. Below this borderline, detergents merely partition into membranes without solubilising membrane proteins.
| Detergent | CMC (%w/v) | CMC (mM) | MW | Type |
|---|---|---|---|---|
| BRIJ 35 | 0.11 | 0.09 | 1200 | non-ionic |
| NP-40 | 0.017 | 0.3 | ~650 | non-ionic |
| Triton X-100 | 0.021 | 0.3 | ~650 | non-ionic |
| Tween 20 | 0.073 | 0.059 | ~1228 | non-ionic |
| SDS | 0.23 | 7-10 | 288.5 | ionic |
| CHAPS | 0.49 | 6-10 | 615 | zwitterionic |
Note: The molecular weights for some detergents are average values. Triton X-100, for example, can range between 600 and over 650 MW depending on synthesis. The exact molecular weight influences the CMC.
