Understanding what the lines on a rapid drug test cup or dip card actually mean. Whether you see one line, two lines, or no lines determines the result.
What you'll need
Supplies:
- Completed drug test device with developed results
Tools:
- Adequate lighting
- Documentation form
Step-by-step procedure
Step 1: Locate the control (C) and test (T) regions
Every rapid drug test has a Control region marked "C" and one or more Test regions marked with substance abbreviations (THC, COC, OPI, AMP, etc.) or "T".
Step 2: Read within the valid time window
Most rapid tests should be read between 5 and 10 minutes after activation. Results read before 5 minutes may be incomplete; results read after 10 minutes may show false positives as the strip dries out.
Step 3: Verify the control line appeared
The C line MUST be visible for the test to be valid. If C is missing, the test is invalid regardless of T line status — retest with a fresh device.
Step 4: Interpret each substance lane
C line + T line (both visible) = NEGATIVE for that substance. C line + NO T line = PRESUMPTIVE POSITIVE for that substance. Even a faint T line counts as negative — partial lines are NOT positives.
Step 5: Document every substance separately
On multi-panel tests, each substance lane reads independently. A 12-panel test may show 11 negatives and 1 presumptive positive. Record each substance result individually.
Step 6: Treat positives as preliminary
A presumptive positive on a rapid screening test is NOT a confirmed result. Send the specimen to a SAMHSA-certified laboratory for GC-MS or LC-MS/MS confirmation, and have a Medical Review Officer verify the lab result before any employment, legal, or medical action.
Questions? Call 318-798-3306 or contact our team. Need supplies in bulk? Request a quote.
