If a unit of platelets has visible clots but appears normal otherwise, what should the technologist do?

When a unit of platelets shows visible clots but appears normal in other respects, it raises a concern for potential microbial contamination or clotting abnormalities. Therefore, quarantining the unit for Gram stain and culture is the most appropriate action.

This step is crucial because visible clots can signal the presence of platelets aggregating due to bacterial growth, which can put recipients at risk for infection or adverse reactions. By conducting a Gram stain and culture, the laboratory can identify if there are any pathogens present, ensuring patient safety before any further use of the blood product.

The other options may not adequately address the risk posed by the visible clots. Issuing the platelets without concern ignores the possible risks associated with microbial contamination. Filtering may remove some clots but does not address the underlying cause or any potential pathogens. Centrifuging the unit to express off the clots may also not resolve the issue and could lead to further complications. Hence, quarantining and testing is the most responsible course of action.