Mohab Mohamed Shalaby : How 'pure' you estimate?

In eventu, cf. ( https://www.uwyo.edu/virtual_edge/results/acidfastresults.html); http://www.uwyo.edu/molb2210_lab/info/lab_03.pdf ); ( https://instr.bact.wisc.edu/book/displayarticle/147 );

( https://www.scienceprofonline.org/science-image-libr/sci-image-libr-acid-fast-stain.html );

( https://www.wiv-isp.be/qml/activities/external_quality/rapports/ATLAS/Bacteriology/Acid-fast-rods.pdf )

;Article Acid-Fast Positive and Acid-Fast Negative Mycobacterium tube...;Article Differentiating between live and dead Mycobacterium smegmati...

BARKSDALE & KIM1977: Mycobacterium in:

BACTERIOLOGICAL Reviews,Mar.1977,p.217-37

https://mmbr.asm.org/content/mmbr/41/1/217.full.pdf

(needs perhaps longer for a complete DL; this one, especially in section: 'Acid fastness', pp. 227- [p.230 - bottom left text column, and ff: cf." .... Mycobacterial cells which have been broken open......!] - 238 )

or:

TREUER & HAYDEL, 2011 (modified Kinyoun acid-fast staining):

Article Acid-Fast Staining and Petroff-Hausser Chamber Counting of M...

(https:__//www.ncbi.nlm.nih.gov/pmc/articles/PMC3071241/pdf/nihms268246.pdf copy and paste into your browser and delete the two underline characters in between 'https: and //www......' to access the original article/authors' manuscript in NIH Public Access )

Guess you use only Ziehl-Neelsen method, what about a control?

You might use - perhaps - auramine-rhodamine (fluorescent) or another staining method , like the Kinyoun method or Kinyoun stain (cold method, either original or modified, the latter using 5% sulfuric acid instead of hydrochloric acid), by BF= basic fuchsin as the initial dye, decolorizing (acid alcohol), counterstain with MB (methylenblue)?

It certainly would be interesting to get feedback - not only by other colleagues in the histological and specialized "field of bacteriology" but also from the inquirer....

Good luck and best wishes...

Hi Mohab: No. I presume that other bacteria (environmental bacilli) are present on the smear. You could culture your sample on Blood Agar plate (at 37C) to detect any contaminant in 24-48 hours.

Good luck