The time resolved immunofluorimetric assay (TRIFMA) - diagnostic method of the future

摘要

This article describes the development and clinical evaluation of two-site immunometric assays for ferritin, thyrotropin (TSH) and tumour necrosis factor alpha (TNFa) using time resolved fluorescent measurement with streptavidin-europium (STAV-Eu{sup}(+3)) as label. The liquid phase antibodies were labelled with amidocaproylbiotin-N-hydroxysuccinimide ester. All three assays were based on microtiterplate technology and could be completed within a working day (incubation times less than 4h). The ferritin assay was compared with luminescent and enzyme labelled assays using identical components. The TSH assay was compared with a commercial immunoluminometric assay whereas the TNF assay was unable to be compared with another method, only with standards from an independent source. The performance data was excellent with lowerdetection limits for TSH from < 0.003 mU/l and for TNFa under 10 ng/l. Intra-assay precision was acceptable within the range of interest with TSH < 4% (0.2-50 mU/l), TNFa < 15% (70-8000 rig/l)) and ferritin < 8% (10-500 g/l). Inter-assay precision was < 6% for TSH, < 16% for TNFa and < 8.5% for ferritin. All assays were performed using commercially available components and proved suitable for routine use.