Level 1 - Workbook
Practice Test - What you need to know for certification
THE RAPID DRUG TEST RESULTS
ACCURACY AND RELIABILITY of rapid drug test comes from the strips and how well the user is able to read them. Although rapid test strips look like a slice of paper, they are actually a complex diagnostic tool that has been perfected over the past 30 years.
1. Rapid drug test strips
WHEN A SAMPLE IS NEGATIVE
DRUG LEVELS BELOW THE CUT-OFF
If a donor sample contains a low amount of drug particles (below cutoff level) or the sample contains no drug particles at all, the reddish chemical (colloidal gold conjugate) will be attracted to the test line. When this occurs, a visual reddish line will appear.
WHEN A SAMPLE IS POSITIVE
DRUG LEVELS ABOVE THE CUT-OFF
If a donor’s sample contains drug particles (above cut-off level), the drug particles will stick to the test line, blocking the reddish chemical. When the drug particles block the reddish chemical, no test line is formed and the reddish chemical flows past the test line area of the strip, leaving it white.