Kinyoun and auramine-rhodamine staining results can be contaminated by tap water. Which statement is accurate?

• A. True
• B. False
• C. Not applicable
• D. Unknown

Answer: (A)

Water quality during the staining process can directly affect the results of acid-fast procedures like Kinyoun and auramine-rhodamine. During rinsing and washing steps, tap water can introduce contaminants or minerals that leave residues on the slide, create background artifacts, or even contribute organisms from the water supply that resemble acid-fast bacilli. Environmental mycobacteria in tap water, plus mineral deposits or organic matter, can be misinterpreted as staining targets or obscure true positives, leading to misleading results. To minimize these risks, rinsing with clean, preferably deionized or distilled water and using freshly prepared reagents is recommended. Therefore, the statement is true.