Science: H7N9 is a subtype of avian influenza virus. Influenza virus particles membrane covered by the two type surface glycoprotein, a type of blood cell agglutinin (H), a type of neuraminidase (N), H was divided into 15 subtypes, N is divided into 9 subtypes. All human influenza viruses can cause avian influenza, but not all of the avian influenza virus can cause a human influenza, avian influenza virus, H3, H5, H7, H9 can infect people, wher H5 is the highly pathogenic. H3 occurs in dogs and humans, according to characteristics of influenza virus can be divided into 135 kinds of HxNx subtypes, H7N9 subtype avian influenza virus is one of them. The biological characteristics of the virus, pathogenicity, the propagation force, is not on the basis of analysis and judgment.

　　

　　Now the lab tests are mostly use RT-PCR (reverse transcription polymerase chain reaction), said that the first PCR (polymerase chain reaction), we all know that DNA is composed of ATCG four base pair double stranded form, the PCR method is to find the peculiar to this virus DNA fragment after addition of the enzyme (is an efficient catalyst) and base (the equivalent of raw materials to production of DNA fragments) can detect the degree. As for the RT (reverse transcription) is to put RNA into DNA.