Although Schistosoma worms infect millions of people today they were evident in ancient Egyptian times, with one of the classic symptoms "haematuria" being described in various medical papyri. A current epidemiology study means diagnostic tools that can be applied to ancient dehydrated tissues are now needed. To overcome this immunocytochemistry has been used, producing positive staining to S. Mansoni and haematobium antigens in both modern and ancient tissues, suggesting that Schistosoma antigens may still be present after thousands of years. Initially, the presence of silica particles enmeshed within ancient tissues made sectioning difficult but this has been overcome by soaking the tissue in a weak solution of hydrofluoric acid which does not disrupt the epitopes whilst the silica dissolves. The application of Immunocytochemistry to ancient tissues has proved to be relatively cheap to perform and may prelude other more complicated tests