Which FISH probe was used for total bacterial counts?

Study for the ACVIM Small Animal Internal Medicine Exam to enhance your veterinary knowledge. Prepare with flashcards and multiple-choice questions, featuring hints and explanations. Ensure success in your exam journey!

Multiple Choice

Which FISH probe was used for total bacterial counts?

Total bacterial counts in FISH are typically assessed with a universal bacterial probe that binds to a conserved region of bacterial 16S rRNA, allowing detection of nearly all bacterial cells in a sample. The Eub338 probe is designed to target that broad range of bacteria, so labeling it with a fluorophore like FITC provides a green signal that marks the entire bacterial population. This makes it the standard choice for counting all bacteria in the sample. In contrast, a probe labeled for Bacteroides would only highlight the Bacteroides group, not the whole bacterial community, so it wouldn’t give a total count. Another universal probe variant might exist, but the commonly used combination for total counts, and the one indicated here, is Eub338 labeled with FITC. The choice with a different fluorophore (such as PE) would detect the same target but in a different fluorescence channel; the fundamental concept—universal bacterial detection—remains the same.

Total bacterial counts in FISH are typically assessed with a universal bacterial probe that binds to a conserved region of bacterial 16S rRNA, allowing detection of nearly all bacterial cells in a sample. The Eub338 probe is designed to target that broad range of bacteria, so labeling it with a fluorophore like FITC provides a green signal that marks the entire bacterial population. This makes it the standard choice for counting all bacteria in the sample.

In contrast, a probe labeled for Bacteroides would only highlight the Bacteroides group, not the whole bacterial community, so it wouldn’t give a total count. Another universal probe variant might exist, but the commonly used combination for total counts, and the one indicated here, is Eub338 labeled with FITC. The choice with a different fluorophore (such as PE) would detect the same target but in a different fluorescence channel; the fundamental concept—universal bacterial detection—remains the same.

More practice questions