Evaluation of a monitor guided nephelometric system

The most common parameters in the specific protein field, namely the immunoglobulins G, A and M were investigated on the recently developed Immuno Video Nephelometer System (IVNS). This system consists of the nephelometer, a microprocessor controlled program and a monitor screen, where instructions, standard curve and results are displayed. Scattered light of immuno-complexes is measured at equilibrium after incubation of prediluted antigen-antibody mixtures. Data were compared with those obtained by radial immunodiffusion (RID), rate nephelometry (Beckman Immunochemistry System-ICS) and immunoturbidimetry (ENI-Gemsaec). Intrabatch variation on the Immuno Video Nephelometer System was found to be good (CV-2.6-3.7%) and day to day variation was satisfactory (CV-3.3-8.6%). There was also good correlation between the values found on the Immuno Video Nephelometer System and those of the other methods (correlation coefficient of 0.94-0.98). Instrumentation advantages, operation procedure and necessity of antigen excess check are discussed in detail.