To prevent nonspecific staining in Grocott-Gomori Methenamine Silver staining due to old chromic acid, which practice is recommended?

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!

Multiple Choice

To prevent nonspecific staining in Grocott-Gomori Methenamine Silver staining due to old chromic acid, which practice is recommended?

In Grocott-Gomori Methenamine Silver staining, the oxidation step relies on chromic acid to generate reactive aldehyde groups that drive the silver reduction onto fungal cell walls. The ability of chromic acid to oxidize properly declines as the reagent ages, and using an old or degraded oxidant can produce nonspecific background staining. The orange color of the chromic acid solution serves as a quick indicator of its strength: if the color is light orange, the oxidizing power is reduced and the solution should be prepared fresh. Fresh chromic acid restores reliable oxidation, leading to specific fungal staining with less background. Using a different oxidant instead of chromic acid would change the chemistry of the stain, which is not desirable for this protocol. Increasing oxidation times can worsen background or damage tissue, and shortening the time in silver solution affects intensity but does not address the underlying issue of insufficient oxidant strength.

In Grocott-Gomori Methenamine Silver staining, the oxidation step relies on chromic acid to generate reactive aldehyde groups that drive the silver reduction onto fungal cell walls. The ability of chromic acid to oxidize properly declines as the reagent ages, and using an old or degraded oxidant can produce nonspecific background staining. The orange color of the chromic acid solution serves as a quick indicator of its strength: if the color is light orange, the oxidizing power is reduced and the solution should be prepared fresh. Fresh chromic acid restores reliable oxidation, leading to specific fungal staining with less background.

Using a different oxidant instead of chromic acid would change the chemistry of the stain, which is not desirable for this protocol. Increasing oxidation times can worsen background or damage tissue, and shortening the time in silver solution affects intensity but does not address the underlying issue of insufficient oxidant strength.

More practice questions