[Histonet] ZN stain

[Michelle Perrins]

Hi
Does anyone have a situation when staining for mycobacterium
tuberculosis with the ZN stain, get negative results in the tissue
sampled but the control is positive, in cases where the patient/deceased
is known to have had TB. I work with autopsy material and have this
situation when we know the person had TB but is negative in the test.
Anyone have any other stain to demonstrate TB bacilli or information on
this issue.

Many thanks

Michelle
Forensic Pathology Services
Western Cape 
South Africa