Evaluation of the flinders technology associates cards for storage and molecular detection of Infectious hypodermal and hematopoietic necrosis virus (IHHNV) DNA

Finders Technology Associates (FTA) cards offer a streamlined solution for the storage, transportation, and extraction of samples. In this study, we assessed the diagnostic efficacy of IHHNV DNA sample storage on FTA cards following simulated transportation under varying conditions (-20°C, 4°C, 25°C, 37°C) over a 60d period. By comparing two elution methods, we determined that optimal results were achieved by performing three elutions with FTA purification reagent at room temperature, followed by two elutions with TE buffer, each lasting 5 min, with a 200 μL elution volume. After the final elution, the membrane was air-dried at room temperature for 1 h before real-time PCR analysis. Our findings revealed that there was no statistically significant difference in nucleic acid preservation with respect to storage temperature and time (P > 0.05). This suggests that nucleic acids stored on FTA cards remained stable under all tested temperature conditions for a minimum of 2 months. For on-site IHHNV monitoring, we analyzed shrimp homogenate samples. Our results demonstrated that eluting and extracting nucleic acid directly from shrimp tissue using FTA cards yielded results comparable in magnitude to conventional reagent kits when analyzed using real-time PCR. This underscores the equivalence of these two methods for nucleic acid extraction. FTA cards prove to be an effective tool for storing and detecting IHHNV DNA samples, offering a convenient and environmentally friendly solution. This method can be routinely employed and easily transported via standard postal systems, making it particularly advantageous for cross-border transportation.