At what temperature should a sample be stored when cooling is used for preservation?

Storing a sample at 4°C, with a tolerance of plus or minus 2°C, is considered optimal for preservation when cooling is applied. This temperature range minimizes microbial growth and enzymatic activity, which can deteriorate the quality of the sample over time. The close-to-freezing temperature helps maintain cell integrity and biochemical stability in various biological and chemical samples.

In laboratory practice, 4°C is commonly used because it is cold enough to inhibit the activity of many pathogens while still allowing for the preservation of the sample's biological properties. This is particularly important for samples such as blood, tissues, or other biological materials that may require short-term storage before testing or analysis. The slight tolerance allows for minor fluctuations in cooling systems without compromising the sample's integrity.