What should be avoided during the collection of a bacteria sample?

Avoiding contact with the inside of the sample bottle cap is crucial when collecting a bacteria sample because this area must remain sterile to prevent contamination. Any unintended touch can introduce organisms present on the fingers or surrounding environment into the sample, which would compromise the accuracy of the test results. Maintaining a sterile technique is paramount in microbiological sampling, as unevaluated bacteria from external sources can lead to false positives or incorrect assessments of the water quality.

Other elements such as exposure to sunlight, sampling during heavy rain, and sampling from stagnant water are also relevant considerations in sample collection. While it is important to minimize sunlight exposure to prevent changes in the sample's biochemical properties and heavy rain can dilute or disrupt sample integrity, these factors do not directly interfere with the inherent sterility of the sample’s protective environment, which is why they are not as critical as avoiding direct contact with the inside of the bottle cap.