If a Gram stain shows over decolorization, which remedy is appropriate?

Study for the CAMLPR Histology Practice Test. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

Over decolorization means the decolorizer has been left on too long, washing the crystal violet-iodine complex from even Gram-positive cells and making them look Gram-negative. The fix is to shorten the decolorization step so that the Gram-positive bacteria retain the violet stain while the Gram-negative cells are properly decolorized and then counterstained. In practice, you’d reduce the exposure to the decolorizer and recheck the slide timing. Using fresh reagents and controls can help verify the process, but the direct remedy for over-decolorization is cutting back the decolorizer time.