What is not maintained by transporting tubes with the stopper up?

Transporting tubes with the stopper facing upward is a method used to help preserve the conditions of the samples during transport. This practice primarily safeguards the integrity of the sample by reducing the risk of contamination and preventing spillage.

The sterility of the sample, while initially important, is contingent upon many factors including the handling and preparation of the sample prior to transport, as well as the way it has been processed and collected. Once the sample is in the tube and sealed, transporting it inverted does not actively maintain its sterility, especially if the sample was exposed to non-sterile conditions before being placed in the tube.

In addition, keeping the stopper up helps to maintain the temperature and the volume of the sample, as it minimizes the potential of mixing or contamination that could affect the sample's characteristics. This method ensures that the delicate balance required for accurate laboratory analysis is preserved, making the integrity and volume of the sample potentially more secure during transport.

Overall, the practice of keeping the stopper up is ineffective for controlling sterility due to the inherent vulnerabilities that come with handling biological samples, whereas integrity, temperature, and volume stand a better chance of being preserved in this position.