A Comparison of the TC10 Automated Cell Counter and the Hemocytometer for Quantifying Insect Hemocytes

Introduction Hemocytes are an essential component of the invertebrate innate immune system (Strand 2008). Their close similarities to vertebrate white blood cells enable their use as a tractable model for immunological research. The quantification of hemocytes in the hemolymph (invertebrate blood) is one way of assessing the efficacy of the immune response because the absolute number of hemocytes changes during the course of an infection (Bergin et al. 2003, Brayner et al. 2007), and the density of hemocytes in the hemolymph is strongly correlated with the capacity to encapsulate or phagocytose parasites (Prevost and Eslin 1998, Kraaijeveld et al. 2001, Wilson et al. 2003, Costa et al. 2005). Most researchers continue to use cell staining and manual microscopy techniques to enumerate the hemocytes in a given sample. However, given the laborious nature of this method (with a throughput often as low as 6–8 samples/hr), more rapid techniques are required to increase our understanding of the role of hemocytes in invertebrate immunology.