Abstract:

False positive results frequently happen in PCR detection of animal and plant components. In order to exclude
the possibility of false positive results, restriction endonuclease digestion was used to confirm the results of PCR for
puffer fish components. Eighteen samples were detected, of which 3 samples were sentenced to be negative whereas the
remaining 15 samples were suspected positive based on PCR results. Restriction endonuclease (NmeA Ⅲ) digestion and
agarose gel electrophoresis were used to analyze the PCR products of the suspected positive puffer fish component. The
electrophoresis patterns of PCR fragments digested by NmeA Ⅲ were different from the positive results of puffer fish in 2
non-puffer fish samples, which were judged as false positive. The electrophoresis patterns of 4 samples of processed puffer
fish with unknown scientific names agreed with those of the puffer fish positive samples and were therefore confirmed.
The PCR products were verified by GenBank DNA sequence homology sequence query (BLAST). In conclusion, a
simple method to confirm PCR results of puffer fish ingredients has been established in this study.

Key words: puffer fish, polymerase chain reaction (PCR) detection, restriction endonuclease, DNA sequence, results confirmation