HBsAg ELISA: comparison of serum and uncentrifuged plasma samples dried on filter paper

To compare the serum and uncentrifuged plasma for hepatitis B surface antigen (HBsAg) enzyme linked immuno sorbent assay (ELISA), ninety samples were analysed. The study was conducted so that in the field, where no amenities are available especially in countries like Pakistan, the separated but uncentrifuged plasma may be preserved by spotting on the filter paper for sero-epidemiological studies later. It was found that there was no statistically significant difference between the serum and uncentrifuged plasma values.