Improved method for determining serum protein concentrations in the far ultraviolet.

We examined the feasibility of measuring absorbance in the far ultraviolet for serum protein determination with a medium-priced, double-beam spectrophotometer. The method has been simplified by using an automatic dilutor to dilute the serum, and a flow-through cell and recorder in conjunction with the spectrophotometer. Because it is only necessary to dilute the serum and determine its absorbance, the procedure is quite rapid. As compared to the biuret reaction, interferences from hemolysis have been about halved. Interferences owing to light scattering by turbid sera have also been appreciably decreased by use of an anionic detegent (sodium dodecyl sulfate) as a serum diluent. Comparisons of the present method to the biuret and Kjeldahl methods indicate that it is relatively accurate, and is practical for routine use.