Randox is a screening instrument that allows for comprehensive and sensitive screening for multiple compounds in a single assay. Randox employs bio-chip technology which works based on ELISA principles (competitive antibody-antigen binding). If drugs are present they will compete with labeled antigens for a limited number of antibody sites. A Chemiluminescent reaction is then used to produce a measurable signal determining if certain drugs/drug classes are present. Randox provides a preliminary screening result, positive results will be followed up with a more specific confirmation test.