What could potentially happen to urine casts if a sample is left unrefrigerated?

Urine casts are microscopic cylindrical structures formed from proteins and cells that can appear in urine. If a urine sample is left unrefrigerated, the casts can dissolve due to the changes in temperature and pH that can occur over time. The proteins and cells that make up the casts are susceptible to decomposing or breaking down when not kept at a stable, cool temperature. This dissolution process can lead to a decrease in the visibility and detectability of casts upon later examination, potentially compromising the diagnostic information gleaned from the urine sample.

Maintaining the sample under appropriate conditions is crucial to preserving the morphology of casts, thus ensuring accurate results during laboratory analysis. Factors like enzyme activity and bacterial growth can also alter the characteristics of the urine, but the primary concern with unrefrigerated casts is their tendency to dissolve.