Long-Term Preservation and Storage of Faecal Samples in Whatman Cards for PCR Detection and Genotyping of and .

Preservation and conservation of biological specimens, including faecal samples, is a challenge in remote areas or poor-resource settings where the cold chain cannot be maintained. This study aims at evaluating the suitability of filter cards for long-term storage of faecal samples of animal and human origin positive to the diarrhoea-causing protozoan parasites, and . Three commercially available Whatman Filter Cards were comparatively assessed: the FTA Classic Card, the FTA Elute Micro Card, and the 903 Protein Saver Card. Human faecal samples positive to ( = 5) and ( = 5) were used to impregnate the selected cards at given storage (1 month, 3 months, and 6 months) periods and temperature (-20 °C, 4 °C, and room temperature) conditions. Parasite DNA was detected by PCR-based methods. Sensitivity assays and quality control procedures to assess suitability for genotyping purposes were conducted. Overall, all three Whatman cards were proven useful for the detection and molecular characterisation of and under the evaluated conditions. Whatman cards represent a simple, safe, and cost-effective option for the transportation, preservation, and storage of faecal samples without the need of the cold chain.