What type of tube should be used to measure trace metals in blood other than lead?

The navy blue top tube is specifically designed for collecting samples that will be tested for trace metals, including mercury, arsenic, and cadmium, among others. This tube is manufactured to minimize potential contamination from the tube itself, ensuring that the measurements of trace metals in the blood are accurate and reliable. The materials used in the navy blue top tube do not contain significant levels of these metals, which is crucial for trace metal analysis given their low concentrations in biological samples.

In contrast, other types of tubes may contain additives or be made from materials that can leach metals into the sample, which would compromise the integrity of the results. For instance, green top tubes contain heparin, which could potentially introduce contaminants. Purple top tubes, typically used for cell counts and other hematological analyses, and red top tubes, which are used for serology tests and blood chemistry, may also not provide the same level of protection against contamination as the navy blue top tube does. Therefore, for accurate measurement of trace metals in blood, the navy blue top tube is the appropriate choice.