02092nas a2200313   4500000000100000008004100001260001300042653001200055653001900067653003200086653001400118653001100132653001200143653000900155653001500164653002500179653003000204653003200234100001300266700001700279700001300296700001500309245008800324856007800412300001100490490000700501520125600508022001401764       1992                            d  c1992 Dec10aAnimals10aDNA, Bacterial10aEvaluation Studies as Topic10aFixatives10aHumans10aleprosy10aMice10aMice, Nude10aMycobacterium leprae10apolymerase chain reaction10aSensitivity and Specificity1 aFiallo P1 aWilliams D L1 aChan G P1 aGillis T P00aEffects of fixation on polymerase chain reaction detection of Mycobacterium leprae.  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC270594/pdf/jcm00036-0077.pdf  a3095-80 v303 a<p>The effects of standard fixatives (10% neutral buffered formalin, ethanol and mercury based) on the detection of Mycobacterium leprae DNA by the polymerase chain reaction (PCR) were studied. Mercury-based fixatives (Zenker's and Carnoy-Lebrun's fluids) strongly inhibited PCR amplification of M. leprae DNA. Ten percent neutral buffered formalin was inhibitory, but significant inhibition was observed only when fixation times exceeded 24 h. Ethanol-based fixatives provided the best medium for holding specimens for subsequent PCR with both free bacilli and skin biopsy specimens containing M. leprae. The M. leprae-specific, 360-bp region of the 18-kDa protein gene could be amplified from paraffin-embedded sections of formalin-fixed skin biopsy specimens from patients with either multibacillary or paucibacillary infections when proper fixation conditions were used. Results of the study demonstrate that tissues properly fixed with two standard fixatives (10% neutral buffered formalin and 50 or 70% ethanol) can be analyzed by PCR for the presence of M. leprae with no loss in specificity and only minimal diminution in sensitivity compared with the specificities and sensitivities obtained by use of freshly prepared, unfixed specimens.</p>  a0095-1137