Hexagon OBTI is the perfect complement to BLUESTAR. This rapid monoclonal antibody screening test verifies that a stain is blood of human origin. HEXAGON OBTI is a two part test: a collection tube for the blood sample, and a test bar. A sample of the presumed human blood trace is transferred into the tube with transport medium. This mixture is added drop by drop to the test. A positive sample is typically detected within 2-3 minutes. Residual sample in the collection tube can be used for DNA typing.