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UND 363 Ziehl/Neelse
UND 363 Ziehl/Neelsen
Question | Answer |
---|---|
purpose for Ziehl-Neelsen (SAME AS KINYOUN EXCEPT FOR A FEW DIFFERENCES) | demo of acid fast mycobacteria |
principle | lipoid capsule of A/F mycobacteria takes up carbol fuchsin and resists decolorization with dilute mineral ACID. |
what is carbol fuchsin more soluble in (lipids of cell wall or acid-alcohol) and how does this affect NON A/F bacteria | it is more soluble in the lipids of the cell wall. NON A/F bacteria lack the waxy capsule and therefore carbol-fuchsin is easily removed |
what does the Phenol and alchol in this stain do? | they aid in dissolving the basic fuchsin |
fix | any well fixed tissue except CARNOYS |
what does Carnoys fixative do to A/F bacteria | It will make them NON A/F |
micron | 4-5 |
Qc | tissue with A/F organisms, must use Millipore filtered (.45 micron pore size) water, and a negative control from same day workload. |
what are the DIFFERENCES from the Kinyoun technique | stain times for carbol fuchsin (30 min. Vs. kinyoun 1hr.), and conc. % of reagents (Phenol/ABSOLUTE/fuchsin 2.5ml/5ml/.5g) Vs. (kinyoun 56ml/95% ALCOHOL 140ml/28g) |
if overstained with methylene blue what will occur and what can be done | it will mask any organisms present. Fix - take slide back to acid alcohol to remove methylene blue, wash with water and repeat counterstain |
why can the sections not be allowed to dry out after carbol fuchsin | a compound that resists decolorization will form |
results | A/F bacteria - bright red, background - lt. blue |
why can tap or distilled water NOT BE USED before the carbol-fuchsin step | there may be bacteria in the piping |
what can Ziehl-Neelsen not be used for and why | mycrobacterium leprae (Must use the FITE stain instead). This bacteria is sensitive to alcohols. |
what must be done after the adic alcohol step (hcl/alcohol) | must be rinsed well before counterstaining or the tissue will not stain |
in the Ziehl-Neelsen what does the carbol fuchsin do? what about the Phenol/alcohol? | C.F. stains the lipid capsule, the phenol and alcohol enhances staining and aids in dissolving of the stain. |