Tissue sample
5µ paraffin sections of neutral buffered formalin fixed tissue are suitable.
Other fixatives are likely to be satisfactory.
Method
Bring sections to water via xylene and ethanol.
Place in solution A for 2 minutes.
Rinse with tap water.
Place in solution B for 1 minute.
Rinse well with tap water.
Blot the slide, but not the tissue.
Decolorise with solution C until no more blue floods off.
Wet section with solution D then apply for 1 minute.
Rinse with distilled water.
Blot the slide, but not the tissue.
Place in acetone for 3 seconds.
Differentiate in solution E for 10 seconds.
Quickly dip a few times in solution F.
Clear with xylene and mount with a resinous medium.
Expected results
Gram positive bacteria – blue
Nocardia and actinomyces – blue, or blue and red
Gram negative bacteria – red
Nuclei, Elastic, Paneth cells – red
Background – yellow
Notes
Picric acid should be handled with care.
Solution E may be made by taking 12 mL of a saturated solution of
picric acid in ethanol and diluting to 1 litre with acetone.
Basic fuchsin homologues with CI numbers of
42500 (pararosanilin) or
42510 (rosanilin) were specified.
It was also noted that new fuchsin
(CI 42520) was satisfactory, but not recommended because it was not certified by
the Biological Stain Commission.
The authors note that sections must not be allowed to dry out
after being stained with basic fuchsin. Doing so makes it difficult or impossible
to properly differentiate the red counterstain.
Reference Churukian, C. J. & Schenk, E. A. (1982) A method for demonstrating Gram-positive and Gram-negative bacteria.
Journal of Histotechnology, v.5, No.3, p.127
