METHOD FOR QUANTITATIVE DETERMINATION OF SPECIES COMPOSITION OF MICROBIOTA OF PARODONTAL RECESSES Russian patent published in 2017 - IPC G01N33/48 C12Q1/68 

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, in particular to dentistry, and is intended for obtaining accurate quantitative data about species composition of microorganisms of parodontal recesses. Content of parodontal recess is used as analysed material. To realise the claimed method sampling of content of parodontal recesses with sterile paper endodontic pin size No 25 introduced into the deepest parts of parodontal recess with exposition not less than 10 sec and placed into test tube with transport medium, is performed. Isolation of total DNA from biomaterial and PCR in real time mode are carried out, with application of species-specific primers to fragments of DNA of Porphyromonas gingivalis, Streptococcus oralis, Streptococcus sanguis, Streptococcus sobrinus, Treponema denticola. After that, concentration of microorganisms in analysed sample is calculated by formula B=1.7×(Nst×E×(Cst-Ct))/V, where: B is concentration of microorganisms, copies of DNA/ml; Nst is standard DNA concentration; E is RT-PCR efficiency - number, showing by how many times quantity of DNA fragments will change in one cycle; Cst is value of threshold cycle of standard sample; Ct is value of threshold cycle of test sample; V is volume of analysed sample, ml; 1.7 is conversion factor.

EFFECT: application of the invention increases accuracy of the method due to determination of concentration of parodontium-pathogenic bacteria in absolute values - quantity of DNA copies/ml.

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