What should be considered when filling a bacteriological sampling bottle?

When filling a bacteriological sampling bottle, it is essential to leave a small air space after filling. This small air space is crucial because it allows for the expansion of water that may occur due to temperature changes and helps prevent spillage during transportation. Additionally, leaving air space can reduce the risk of contamination or oxygenation that may affect the sample, which is critical for accurate bacteriological analysis. It ensures that the sample remains uncontaminated and that microbial growth occurs in a controlled environment, leading to more reliable test results.

In contrast, filling the bottle completely to the top could lead to issues with overflow and contamination. Using distilled water is not necessary for sampling, as the goal is to collect the water being tested, not to introduce a different sample. Sealing the bottle immediately after filling is important for preventing contamination, but this step does not specifically address the proper filling of the bottle itself, making it less pertinent to the question asked. Therefore, achieving the correct filling method is fundamental for the integrity of the bacteriological sample collected.