Quantum dot-fluorescence in situ hybridisation for Ectromelia virus detection based on biotin–streptavidin interactions

Ectromelia virus (ECTV) is an pathogen that can lead to a lethal, acute toxic disease known as mousepox in mice. Prevention and control of ECTV infection requires the establishment of a rapid and sensitive diagnostic system for detecting the virus. In the present study, we developed a method of quantum-dot-fluorescence based in situ hybridisation for detecting ECTV genome DNA. Using biotin–dUTP to replace dTTP, biotin was incorporated into a DNA probe during polymerase chain reaction. High sensitivity and specificity of ECTV DNA detection were displayed by fluorescent quantum dots based on biotin–streptavidin interactions. ECTV DNA was then detected by streptavidin-conjugated quantum dots that bound the biotin-labelled probe. Results indicated that the established method can visualise ECTV genomic DNA in both infected cells and mouse tissues. To our knowledge, this is the first study reporting quantum-dot-fluorescence based in situ hybridisation for the detection of viral nucleic acids, providing a reference for the identification and detection of other viruses.