Aims α-Naphthyl acetate esterase (ANAE) is one of the few enzymes that are histochemically detectable on formalin-fixed paraffin-embedded tissue. In bone marrow (BM) biopsies, ANAE staining highlights megakaryocytes. We investigated autopsy BM to determine whether ANAE staining intensity (SI) was associated with postmortem intervals (PMI, period between death and autopsy), and thus could allow the time of death of a patient to be deduced.

Methods ANAE-stained BM slides of 74 forensic and pathology autopsies as well as 22 biopsies were histologically evaluated and their SIs semiquantitatively graded.

Results ANAE-SIs did not differ between men and women and slightly decreased with age. Biopsies had significantly higher ANAE-SIs than pathology cases. In autopsies, ANAE-SIs were not associated with PMI, except for cases with PMI ≥7 days which were consistently ANAE-negative.

Conclusions ANAE-SIs in postmortem BM samples were independent of PMI. Thus, ANAE staining of BM megakaryocytes cannot serve as an indicator for time-since-death of a patient.