In tissue processing, the presence of what indicates incomplete precipitation?

In tissue processing, the presence of a cloudy solution indicates incomplete precipitation. When a reagent is added to a solution intended to promote precipitation, such as during the fixation or embedding process, ideally, the precipitate should settle out clearly, leaving a clear supernatant. If the solution remains cloudy, this suggests that the particles have not completely aggregated or settled. This cloudiness is often a result of residual solute or particles that have not been effectively removed from the solution, signaling that the precipitation process has not reached completion. Consequently, the cloudy appearance indicates that further processing may be necessary to ensure that excess chemicals or particulates do not interfere with subsequent histological evaluations or analyses.