What action should be taken first if a dish of amniotic fluid culture appears contaminated?

When a dish of amniotic fluid culture shows signs of contamination, the first and most critical action is to report the contamination to the supervisor. This course of action is paramount because it ensures that proper protocols are followed to address the contamination issue as well as safeguard the integrity of the laboratory results and workflows.

Reporting the contamination allows for an assessment of the potential impact on the validity of the culture and any downstream analyses. It also enables the laboratory to initiate appropriate corrective measures, which may include isolating the contaminated culture, evaluating all related samples, and determining whether additional cultures need to be initiated.

Harvesting the culture without first addressing the contamination not only risks invalidating the results but can also compromise the analysis of sample integrity. Ignoring the problem or merely monitoring other cultures fails to mitigate the risk posed by the contamination, potentially leading to further issues down the line. Changing the environment of the culture may not resolve the contamination either and could instead lead to further complications.

Thus, the best action in the event of contamination is to promptly inform a supervisor, ensuring that the situation is handled appropriately and following established laboratory protocols.