We have considered four general aspects of PCR typing during
which contamination might occur: amplification set-up, handling
of amplification product, aerosolization, and DNA storage. To define
precisely the parameters affecting PCR contamination, PCR
reactions were intentionally compromised by employing sub-standard
laboratory techniques and by introducing secondary sources
of DNA. Our standard casework protocols for the PM 1DQA1 test
were used, and detection was by reverse dot blot. The results
demonstrate that contamination was possible, primarily when gross
deviations from standard laboratory procedures were practiced.
Our study provides evidence that contamination is difficult to
achieve when using the dot blot detection method in PCR analysis.