In the current study, attempts were also made to generate mAbs using fully washed B. PS-1145 anthracis PFI-2 spores as an immunogen. Unexpectedly, we identified three high affinity mAbs capable of direct and species-specific recognition of both B. anthracis spores and vegetative cells. Furthermore, these mAbs were all directed against the EA1 protein, which is well known as a major S-Layer protein in B. anthracis vegetative cells. Some recent studies have revealed that EA1 is also retained in the proteomic profiling of rigorous washed spores and even salt/detergent washed exosporium. Although Williams and Turnbough suggested EA1 was not a true spore surface protein, they stated this protein persistently existed in the spore surface. Therefore, it is valid to use EA1 as a detection target of B. anthracis spores herein, as EA1 is highly associated with the spore surface. In this study, we conclude that the mAbs we prepared, directed against EA1, can recognize the surface of B. anthracis spores as well as vegetative cells, and we also suggest EA1 protein can serve as a potential marker for the detection of B. anthracis. This study is significant because until now, there have been no monoclonal antibodies reported for direct and speciesspecific detection of both life forms of B. anthracis. To guarantee the purity of spores that we prepared, both unwashed and fully washed spores were analysed by AFM. As is shown in Figure 1, a larger amount of free spores appeared. Even the unwashed spores were surprisingly clean, as no intact vegetative cells and little vegetative cell debris were present. However, because it is likely that some vegetative cell proteins will bind accidentally to the spore surface, the rigorous washing method, as described above, was still employed. There were few differences between the unwashed spores and fully washed spores, but the latter seemed to have a much smoother surface than the former, indicating that our spore purification protocol had removed some unknown material.