[Histonet] Tissue Gram stain controls

[Bob Richmond]

Naveeda Arshad (where?) asks: >>Does any one has idea about how to
make in house gram positive and negative control in your lab? What
kind of tissue is suitable and and i need detail procedure for that?<<

Usually a section of a ruptured appendix (easy enough to get in a
hospital histology lab) will provide an abundance of suitable
bacteria.

A better solution is not to do a tissue Gram stain at all. You want to
see bacteria - you really can't identify them in tissue sections. A
simple tissue Giemsa or Diff-Quik II stain is both sensitive and
specific for seeing bacteria of all kinds. (The ruptured appendix will
work well as a control.) Pathologists are much too ready to order a
stain that's of very dubious clinical value, particularly since tissue
Gram stains usually stain Gram negative organisms rather weakly.

Bob Richmond
Samurai Pathologist
Knoxville TN