kDa
kilodalton (as molar mass)
The kilodalton is 1000 daltons, 1.00000000105 kg/mol as a molar mass. It is the working unit of protein biochemistry: albumin is 66 kDa, an antibody 150 kDa, and a gel is read off in kDa against a ladder of standards.
Watch out: Gel and size-exclusion estimates of kDa are apparent masses. Glycosylation, shape and detergent binding all move the number, sometimes by tens of percent, which is why a mass spectrometer and a gel can disagree about the same protein.
| 1 kDa | 1,000 g/mol |
Solvers that use molar mass