Which of the following specimens requires a chain of custody form?

While blood samples for HIV testing are important for medical diagnosis, they do not typically require a chain of custody form. These tests are generally conducted in a clinical setting where the focus is on patient care rather than legal evidence, thus allowing for confidentiality and standard medical protocols without the need for strict chain of custody documentation.

Sputum samples for tuberculosis testing are collected for clinical diagnosis rather than legal purposes. The focus in these cases is on public health and treatment, and the samples do not necessitate a chain of custody as they are not used in legal scenarios requiring documented integrity of evidence.

Similar to the previous examples, swabs for chlamydia testing are used for medical diagnosis and treatment. These specimens are collected in a clinical context where maintaining a chain of custody is not required, as the results are typically for personal health management rather than legal proceedings.