Final answer:
In the Single Intradermal Comparative Cervical Tuberculin test, used to diagnose tuberculosis, the recommended distance between the two injection sites is typically 12 centimeters to ensure accurate test interpretation.
Step-by-step explanation:
The distance between the two injection sites in the Single Intradermal Comparative Cervical Tuberculin (SICCT) test, which is a form of tuberculin test for diagnosing tuberculosis (TB), is typically 12 centimeters (cm). This distance is recommended to prevent interference between the test sites and to enable accurate reading of the skin's response. A positive SICCT test is indicated by a significant difference in the size of the reactions at the two injection sites, which suggests the presence of a cell-mediated immune response to Mycobacterium tuberculosis.