Page 82 - MNUmicrobiology practical 2025
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General Microbiology & Immunology (PM 401) second level Semester 4 2024/2025
3- Clean microscope slides
4- Modified Ziehl Neelsen staining reagents
- Carbol fuchsin [primary stain]
- (0.25% -0.5 %H2so4)[ Decolorizing agent]
-Methylene blue [counterstain]
5- Inoculating loop
6-Bunsen burner
7- Slide holder.
8- Staining rack
10- Washing water
10- Microscope with oil immersion lens
12- Marker pen
Modified Ziehl Neelsen staining steps
1- Prepare of bacterial smear
2- Flood the smear with the primary stain (carbol
fuchsin), place it in a boiling water bath over
hot plate, and let it sit for 5 minutes (gentle
heat or steam act as a mordant as it helps in
penetration and retention of dye)
3- Reapplying stain if it begins to dry out
4- Let the glass slide cool and wash the smear with slow-running water
5- Decolorize with 6 drops of (0.25% -0.5 %H2so4) for 10 – 15 seconds, then
rinse with water.
General Microbiology & Immunology (PM 401) Practical note Page 71