Abstract
Aims—To evaluate factors which ameliorate false positive artefacts with direct in situ PCR using labelled dNTPs; to investigate the use of labelled primers to overcome this artefact whilst maintaining sensitivity.
Methods—Sections of measles (RNA virus) infected Vero cells with cytoplasmic signal or cytomegalovirus (DNA virus) infected fibroblasts with nuclear signal were collected. In situ PCR (or in situ RT-PCR) was carried out by methods permitting evaporation. Reagents or conditions which may control false positive artefacts using labelled dNTPs were investigated systematically. Labelled primers were tested to overcome artefacts, with adjuncts which improve sensitivity.
Results—No reagent nor condition investigated was able to control the artefact with labelled dNTPs. Excessive digestion and incomplete DNAse treatments exacerbated the artefact, whereas novobiocin decreased both specific signal and artefact. However, the artefact was controlled by labelled primers, albeit with relatively low sensitivity. Sensitivity using labelled primers could be increased using alcohol fixation, albumin or Perfectmatch.
Conclusions—A repair process is implicated for the artefact using labelled dNTPs. Excessive digestion or DNAse treatment may exacerbate DNA damage by disrupting histones or the DNA, respectively. Labelled primers control this artefact, albeit with reduced sensitivity, which may be improved by precipitation fixatives (alcohol) and reagents which enhance specific reaction.
Keywords: in situ nucleic acid amplification
Keywords: artefacts
Keywords: labelled primers
Full text
PDF





Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cosby S. L., McQuaid S., Taylor M. J., Bailey M., Rima B. K., Martin S. J., Allen I. V. Examination of eight cases of multiple sclerosis and 56 neurological and non-neurological controls for genomic sequences of measles virus, canine distemper virus, simian virus 5 and rubella virus. J Gen Virol. 1989 Aug;70(Pt 8):2027–2036. doi: 10.1099/0022-1317-70-8-2027. [DOI] [PubMed] [Google Scholar]
- Cranage M. P., Kouzarides T., Bankier A. T., Satchwell S., Weston K., Tomlinson P., Barrell B., Hart H., Bell S. E., Minson A. C. Identification of the human cytomegalovirus glycoprotein B gene and induction of neutralizing antibodies via its expression in recombinant vaccinia virus. EMBO J. 1986 Nov;5(11):3057–3063. doi: 10.1002/j.1460-2075.1986.tb04606.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Haase A. T., Retzel E. F., Staskus K. A. Amplification and detection of lentiviral DNA inside cells. Proc Natl Acad Sci U S A. 1990 Jul;87(13):4971–4975. doi: 10.1073/pnas.87.13.4971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hammond R. A., McClung J. K., Miller M. R. Effect of DNA polymerase inhibitors on DNA repair in intact and permeable human fibroblasts: evidence that DNA polymerases delta and beta are involved in DNA repair synthesis induced by N-methyl-N'-nitro-N-nitrosoguanidine. Biochemistry. 1990 Jan 9;29(1):286–291. doi: 10.1021/bi00453a039. [DOI] [PubMed] [Google Scholar]
- Komminoth P., Long A. A. In-situ polymerase chain reaction. An overview of methods, applications and limitations of a new molecular technique. Virchows Arch B Cell Pathol Incl Mol Pathol. 1993;64(2):67–73. [PubMed] [Google Scholar]
- Long A. A., Komminoth P., Lee E., Wolfe H. J. Comparison of indirect and direct in-situ polymerase chain reaction in cell preparations and tissue sections. Detection of viral DNA, gene rearrangements and chromosomal translocations. Histochemistry. 1993 Feb;99(2):151–162. doi: 10.1007/BF00571876. [DOI] [PubMed] [Google Scholar]
- Ray R. A., Smith M., Sim R., Nystrom M., Pounder R. E., Wakefield A. J. The intracellular polymerase chain reaction for small CMV genomic sequences within heavily infected cellular sections. J Pathol. 1995 Oct;177(2):171–180. doi: 10.1002/path.1711770211. [DOI] [PubMed] [Google Scholar]
- Roberts J. D., Thomas D. C., Kunkel T. A. Exonucleolytic proofreading of leading and lagging strand DNA replication errors. Proc Natl Acad Sci U S A. 1991 Apr 15;88(8):3465–3469. doi: 10.1073/pnas.88.8.3465. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Taylor M. J., Godfrey E., Baczko K., ter Meulen V., Wild T. F., Rima B. K. Identification of several different lineages of measles virus. J Gen Virol. 1991 Jan;72(Pt 1):83–88. doi: 10.1099/0022-1317-72-1-83. [DOI] [PubMed] [Google Scholar]
- Wakefield A. J., Pittilo R. M., Sim R., Cosby S. L., Stephenson J. R., Dhillon A. P., Pounder R. E. Evidence of persistent measles virus infection in Crohn's disease. J Med Virol. 1993 Apr;39(4):345–353. doi: 10.1002/jmv.1890390415. [DOI] [PubMed] [Google Scholar]


