Which statement is true regarding fluorescent gels in cleaning verification?

• A. ATP markers are applied before cleaning.
• B. Fluorescent gels are applied after cleaning.
• C. Fluorescent gels are applied before cleaning and indicate soil removal.
• D. ATP markers are used to indicate soil removal.

Answer: (C)

Fluorescent gels in cleaning verification are used as a soil surrogate that you apply before cleaning. After cleaning, you inspect the surface under UV light to see whether the gel has been removed. If the fluorescent gel remains, soil wasn’t effectively removed in that area; if it’s gone, cleaning was successful. This is why the statement describing applying the gel before cleaning and using its removal as an indicator of soil removal best captures how these gels function.

ATP markers, by contrast, are used after cleaning to detect residual organic material, not applied before cleaning, and they don’t directly indicate soil removal.