DNA microarray for detection of unknown virus in clinical specimens

Objective To develop a DNA microarray for detection of unknown virus in clinical specimens.Methods Probes for dengue virus type 1-4 were designed and synthesized,and DNA microarray of dengue virus was prepared.After viral RNA of dengue virus type 1-4 standard strains were extracted,whole genome amplification was performed by using phi29 DNA polymerase and a random primer contain tag sequence,then the genome was amplified and labeled by random PCR with a Cy3-conjugated tag sequence primer.The fluorescein labeled amplicon were subjected to hybridization with the DNA microarray of dengue virus.Whereafter the novel method was verified by using serum samples collected from pateints with dengue fever in Guangzhou Baiyun airport entry and exit inspection and quarantine frontier port. Results Hybridization signals of dengue virus type 1-4 standard strains were significantly distinguished,and all of the related strains showed a high probe positive rate of 100%.Similarly,3 serum samples of dengue virus from clinical patients also had significant hybridization signals with very low background noise.Dengue virus types 1,2 and 3 carried in the 3 serum samples can be clearly identified by the high probe positive rate of 100% related to the microarray.Conclusion The innovative DNA microarray assay can be used to detect dengue virus in clinical specimens.If more specific probes for different species of pathogens are designed and appended to this new DNA microarray,it also can be expanded for unknown pathogens identification in clinical specimens.