[Solid-phase immunoenzyme analysis of insulin using Bacillus licheniformis 749/c beta-lactamase and horseradish...

Two modifications of solid phase enzyme immunoassay (EIAA) for insulin with the use of beta-lactamase from B. licheniformis 749/c and horse radish peroxidase as the markers were developed. beta-Lactamase and peroxidase conjugates with insulin were prepared with the glutaric aldehyde and periodate methods respectively. Both the conjugates were stable and preserved high immunospecific and enzymatic activity. Sensitivity of EIAA with the use of the beta-lactamase or peroxidase as the markers was the same and amounted to 15 ng/ml of insulin. However, with the use of the beta-lactamase in EIAA not only spectrophotometric recording but also visual registration of the results was possible.