Use "contaminant" in a sentence

1. The computer programs to this day are still inferior at predicting to any degree of certainty how a specific cultural contaminant might manifest itself

2. Pearl # 2: Candida in the blood is not a contaminant, but could be in the sputum or

3.  Coagulase-negative staphylococci is a contaminant in blood cultures about 82% of the

4. Isn’t there a chance that some contaminant has come down to the river?”