Which item is indicative of a lower quality specimen based on a Q-Score?

A lower quality specimen can often be assessed through the presence of certain types of cells, and epithelial cells are a key indicator of potential contamination or specimen quality issues. The presence of epithelial cells in a specimen, particularly in certain types of samples like urine or sputum, may suggest that the sample has been contaminated by tissue from the surrounding areas rather than representing the target tissue or fluid of interest.

In laboratory practice, high-quality specimens usually have a specific cellular composition that reflects the target diagnosis. Epithelial cells, being derived from the lining of organs and surfaces, can skew results and indicate that the specimen may not be reliable for accurate analysis of the intended markers or pathogens. Thus, their predominance in a specimen like a urine sample can raise red flags and diminish the specimen's overall quality score, known as a Q-Score.

This concept emphasizes the importance of collecting specimens in a manner that minimizes contamination to ensure that laboratory results are both accurate and valid for diagnostic purposes. The presence of red blood cells, platelets, and white blood cells can be expected in certain contexts and may not inherently diminish specimen quality unless in abnormal quantities or contexts.