Gold immunochromatography for HBsAg detection

Objectives To evaluate the quality and performance of 4 sources of gold immunochromatography assay (GICA) strips for HBsAg detection and to provide data for various laboratories in the selection of HBsAg assay methods. Methods Several known sera and 2158 unknown sera were tested with both GICA strips and EIA. The sensitivity, specificity and physical properties of the strips were assessed. Results The minimal detection limits of the 4 sources of GICA strips were 1-5 ng/ml, with detection rates varying from 95.6 to 98.7%, as compared with EIA. No false positives and pre band phenomena were found. GICA needed 5 to 30 min to complete. It costed 4 or 5 times as much as EIA. Conclusions GICA is fit for emergency and rapid screening of blood donors. It is less sensitive than EIA, and costs more. In blood donor screening, GICA should be combined with EIA, since screening only by GICA may not be reliable.