Friday, September 21, 2007

Mad Scientist

You are playing around with a slide. While heating it, you pipet a bit of phenol plus this:

You then wash it a bit with water and acid alcohol before adding:

This is what you see:

This picture is a clinical correlation:

Nothing can be cultured out.

Challenge: What is the diagnosis?

Related Questions:
1. What's the stain used?
2. What is the significance of nothing being cultured out?

All images are in the public domain.

1 comment:

Craig said...

Mad Scientist

This stain is a Ziehl-Neelson or acid-fast stain to identify acid-fast mycobacteria like Mycobacterium tuberculosis. The first reagent is carbol fuchsin, a mixture of phenol and basic fuchsin; the molecule shown is fuchsine. The slide is then washed in water and acid alcohol, then counterstained with methylene blue, the second chemical shown. The histology image shows acid-fast bacteria Mycobacterium leprae. The image shows cutaneous leprosy lesions. However, the mycobacterium cannot be cultured out in artificial media because it lacks genes for independent growth. It can be grown in armadillos or mouse foot pads as a diagnostic test. The disease is leprosy or Hansen’s disease.

Source: Wikipedia.

(NB: Sorry Alex, your comment got deleted by accident, but good job anyway :P)