T. Victor et al., LABORATORY EXPERIENCE AND GUIDELINES FOR AVOIDING FALSE-POSITIVE POLYMERASE CHAIN-REACTION RESULTS, European journal of clinical chemistry and clinical biochemistry, 31(8), 1993, pp. 531-535
Despite the widespread use of polymerase chain reaction (PCR) for diag
nosis of infectious diseases, the technology has not been generally in
troduced into routine diagnostic laboratories. One of the most serious
problems which has influenced the acceptance of this technology is th
e occurrence of false positive PCR results. This study describes the e
xperience, in a hospital laboratory setting, of using PCR for the diag
nosis of heat-labile enterotoxin-producing E. coli, M. tuberculosis, M
. paratuberculosis and human papillomavirus. Results indicate that a b
uild-up of amplicons, generated during the amplification process in th
e laboratory, is the main source of PCR-contamination. Protocols are d
escribed that include both physical and chemical procedures to prevent
contamination. The use of photo-induced psoralen is recommended for t
hose laboratories already involved in PCR work where amplicons are lik
ely to be present. An enzymatic system (uracil-N-glycosylase) was eval
uated and is recommended for workers intending to start diagnostic PCR
. Attention was given to simple control measures which are easily impl
emented in a routine diagnostic laboratory. Protocols such as these ar
e likely to have a major impact on the introduction of PCR-based metho
ds into routine laboratories.