Fig. 3

Progressively magnified photomicrographs of adjacent HP tissue sections stained with H&E (Column 1) or showing in situ hybridization results using a DIG-labeled probe for E. hepatopenaei (EHP) (Column 2). a Low magnification (10x objective) showing that E. hepatopenaei (EHP) cannot be resolved by H&E staining. b Adjacent tissue section showing that focal areas of E. hepatopenaei (EHP) infection can be easily detected by a DIG-labeled probe. c No probe negative control showing some regions of non-specific signal (arrows) also present in (b) (similar arrows). d Higher magnification (40x objective) of the area outlined in (a) showing that E. hepatopenaei (EHP) still cannot be easily resolved. eAdjacent section showing that E. hepatopenaei (EHP) spores cannot be easily resolved by the DIG probe. f Higher magnification (100x objective) of the area outlined in (d) showing spores and intracellular plasmodia of E. hepatopenaei (EHP) that are just visible. Squares outline regions that are magnified in (h) and (j) to make the spores and plasmodia easier to see. g and i Adjacent sections showing a magnified region of (g) making it easier to see E. hepatopenaei (EHP) spores labeled by the DIG probe