Simplifying the process of extracting intestinal parasite eggs from archaeological sediment samples: A comparative study of the efficacy of widely-used disaggregation techniques.

Some scientific techniques are widely used because they work satisfactorily, but they may not be the cheapest, fastest or most efficient method possible. Here we assess the widely used methods for disaggregating archaeological latrine sediments, where solid soils are converted to aqueous suspension prior to microscopic analysis for ancient parasite eggs. It has been noted that there is great variability in protocols described in the published literature. We have used samples from a medieval latrine in Cyprus and a cesspool from Israel containing roundworm eggs to evaluate in a pilot study whether there appears to be distinct advantages to any of the standard protocols. The results suggest that there is very little difference in the efficacy whether disaggregation is performed using traditional 0.5% trisodium phosphate or simple distilled water, whether the process lasts 72h or just 1h, or whether sonication is added to the process. While a larger sample size would allow a more robust statistical analysis, this pilot study provides no evidence to suggest the long disaggregation periods, expensive chemicals, or sonication steps leads to any better disaggregation in latrine sediments than using distilled water for just 1h.