Laser nephelometric measurement of seven serum proteins compared with radial immunodiffusion

Quantification of immunoglobulins IgG, IgA, IgM, C3 complement, siderophilin, alpha 2-macroglobulin and haptoglobin in serum by a Behring laser nephelometer coupled with a date processing apparatus was compared with values obtained by the radial immunodiffusion method of Mancini. The precision was not improved by the use of the laser nephelometer as compared to Mancini radial immunodiffusion, but within run precision was better than that among runs for both methods. The analytical recovery studies for laser nephelometry showed a close concordance between the theoretical and measured values for all proteins. The two techniques were also compared by means of correlation studies.