Combination of fixation using PLP fixative and embedding in paraffin by the AMeX method is useful for histochemical studies in assessment of immunotoxicity.

To establish a method for processing lymphoid organs suited to morphological, immunohistochemical and enzyme histochemical analyses for assessment of immunotoxicity, we examined a combination of fixation with periodate-lysine-paraformaldehyde (PLP) fixative and embedding in paraffin by the AMeX method (PLP-AMeX method). Spleen and thymus removed from monkeys and rats were fixed in PLP fixative for 6 hours at 4 degrees C. After fixation, specimens were processed and embedded in paraffin by the AMeX method.