Detection of specific interferon gamma (IFN-γ) responses can aid in the diagnosis of paratuberculosis. IFN-γ detection assays offer the potential to identify more infected animals at an earlier stage of the disease than antibody ELISA. A logistical limitation to the application of IFN-γ assays has been the assay needs to be performed within 8hr of blood collection. Research has shown that, for blood samples with a delayed assay setup (24hr), addition of Interleukin (IL)-12 can rescue the IFN- production. For countries such as Australia, however, samples may take 2 days to reach a laboratory; therefore an improved protocol was required. IL-7 is a survival factor required to maintain resting T cells. We hypothesised that IL-7 alone or in combination with IL-12, could extend blood storage time. The combination of IL-7 and IL-12 had a synergistic effect allowing blood to be stored for up to 2 days. The same number of animals could be identified as test positive after blood was stored for 2 days using the modified IL-7 and IL-12 assay compared to the traditional assay. This practical and easily implemented potentiation protocol extends the permissible transit time of blood samples from farm to laboratory for IFN-γ detection.