The VDRL (Venereal Disease Research Laboratory) Test and RPR (Rapid Plasma Reagin) Test are blood tests used to screen for syphilis. Both tests detect antibodies produced by the body in response to the syphilis bacteria. The tests are performed by taking a blood sample from a vein in the arm and analyzing it in a laboratory. A positive result may indicate a current or past syphilis infection and further testing and treatment may be necessary.