Abstract
In an attempt to find a convenient method for the seroepidemiological study of HBsAg in developing countries, ELISA using blood samples dried on filter paper was evaluated. The results of this method were in complete agreement with both those obtained on original sera by RIA and with those obtained on sera by ELISA. We did not experience any false positive or false negative results. In this study the sample dried on filter paper was eluted by 1 ml of PBS (pH 7.2). Dilution rates were calculated by the calibration line of each serum. Dilution rates were between 0.041 and 0.082. The coefficient of variation of absorbance value of 10 samples of each case was between 5.0% and 14.8%, which indicated an acceptable intratest reproducibility of this method. In addition, storage at 20°C, 20°C with desiccants and 3°C for up to 21 days did not alter the sensitivity and specificity of this method. This method will be useful for the seroepidemiological study of HBV in developing countries.
