Microbiological testing
For the MRCEM exam you should be familiar with the following stains:
Although knowledge of the above is expected this doesn't mean that they are gold standard tests. Malaria for example should be diagnosed following multiple blood films (usually 3 sets within 36 hours and often examined under flurescent microscope) whilst TB should have formal cultures.
| Stain | Used to detect | Specimen |
|---|---|---|
| ZN (Ziehl Neelsen stain) | acid fast bacilli i.e TB | sputum |
| Giemsa | malaria | blood film |
| Gram | Various bacteria | Blood/sputum/CSF/others |
Although knowledge of the above is expected this doesn't mean that they are gold standard tests. Malaria for example should be diagnosed following multiple blood films (usually 3 sets within 36 hours and often examined under flurescent microscope) whilst TB should have formal cultures.