Lysozyme determined in serum or urine by a simple nephelometric method.

We describe a nephelometric procedure for determination of lysozyme. A quantitative result is obtained in 2 to 3 min with 50 microliter of serum or urine. At a lysozyme concentration of 12.0 mg/liter, between-day precision was 3.4% and the analytical recovery 96.5-105.5%. The values obtained were a linear function of enzyme concentration below 50 mg/liter, and they agreed with those obtained by absorptiometric determination of the decrease in turbidity of a suspension of Micrococcus lysodeikticus.