Quantitative automated latex nephelometric immunoassay for determination of myoglobin in human serum

We have evaluated a new latex nephelometric test for the quantitation of myoglobin in human serum. The assay consists of incubating the diluted serum sample (20-fold) for 12 min at room temperature with latex particles covalently coated with anti-myoglobin antibodies and then quantifying the change of light-scatter produced. The assay is fully automated on the Behring nephelometer analyzer with a sampling rate of 150 samples/hour. There is no interference from bilirubin (up to 340 mumol/l), haemoglobin (up to 7,000 mg/l), or rheumatoid factor (up to 1,100 int. units/ml). Myoglobin standard curve extends from 20 to 380 micrograms/l. Assay detection limit lies around 6 micrograms/l. Coefficient of variation ranged from 2.7 to 7.6%. Correlation coefficient between latex immunoassay and an RIA method was 0.987, calculated from the assay of 37 samples. A statistically significant difference was found between the distribution for females and males. The serum level of myoglobin showed an age-dependent variation. Concentrations up to 60 micrograms/l are considered to be normal.