What is typically used for sample preservation in many laboratory tests?

In laboratory testing, acids or bases are commonly used for sample preservation because they can help maintain the integrity of the sample and prevent chemical changes that could occur during storage. The addition of acids, for instance, can lower the pH of a sample, thereby inhibiting the growth of microorganisms and slowing down biochemical reactions that could alter the results of the analysis. In environmental testing, for example, acidifying water samples is essential for preserving certain parameters such as metals, preventing them from precipitating or changing chemical forms.

Using acids or bases is a well-established practice within laboratory protocols to ensure that the sample remains stable until it can be analyzed. The choice of acid or base often depends on the specific requirements of the analysis being conducted and the type of sample being preserved.