If a CSF sample for VDRL testing is delayed because the test is unavailable, what is the recommended interim handling?

If a CSF sample for VDRL testing is delayed because the test is unavailable, what is the recommended interim handling?

• A. Report RPR as negative
• B. Call the physician and cancel the test
• C. Freeze the CSF sample and wait for the VDRL to be available
• D. Repeat RPR but inactivate CSF first

Answer: (C)

When a CSF sample for VDRL testing can’t be processed right away, the priority is to preserve the sample so the test result will be reliable later. Freezing the CSF promptly is the best interim handling because it slows or stops degradation of antibodies and preserves the sample’s reactivity for when the VDRL can be performed. Store at a cold temperature (typically -20°C or colder) and avoid multiple freeze–thaw cycles. Reporting a result or canceling the test isn’t appropriate because no result exists yet. Inactivating the CSF or repeating the test with a different method isn’t standard practice for this scenario and could alter the testing outcome.

When a CSF sample for VDRL testing can’t be processed right away, the priority is to preserve the sample so the test result will be reliable later. Freezing the CSF promptly is the best interim handling because it slows or stops degradation of antibodies and preserves the sample’s reactivity for when the VDRL can be performed. Store at a cold temperature (typically -20°C or colder) and avoid multiple freeze–thaw cycles.

Reporting a result or canceling the test isn’t appropriate because no result exists yet. Inactivating the CSF or repeating the test with a different method isn’t standard practice for this scenario and could alter the testing outcome.