[dogma1138]

Single swab tests may be inaccurate, nasal, throat and anal swabbing is usually recommended for good coverage.

The PCR test itself has near 100% sensitivity and specificity when done correctly.

Poor swabbing or contamination can result in false negatives or positives.

Manual PCR testing is known to be quite prone to human errors hence why the all in one cassette kits are quite popular.