METHOD OF ASSESSING THE COMPOSITION OF BIOFILMS OF GRAM-POSITIVE BACTERIA Russian patent published in 2019 - IPC G01N33/52 C12Q1/00 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to microbiology, infectious diseases, disinfectology, and can be used to study action of factors on biofilm and biofilm-forming ability of gram-positive microorganisms. Method for assessing composition of biofilms of gram-positive bacteria formed in polystyrene plates is carried out using 0.1 % aqueous solution of gentian violet with its extraction with alcohol and photometry of samples at wave length 560 nm, wherein coloring with gentian violet is carried out for 5 minutes with subsequent fixation of dye in bacterial cells by Lugol's solution, colored products are dissolved with 70 % alcohol: matrix components for 1 minute, total biofilm for 15 minutes, after which biofilm composition is evaluated by formulas M=(OP_bw/OP₁₅)×100; Kb = 100-M, where M is matrix fraction, %; Kb – fraction of cellular component, %; OP_bw – optical density of samples, when alcohol for dissolution of colored product is held for not more than 1 minute; OP₁₅ is the optical density of the samples when the alcohol is dissolved for 15 minutes to dissolve the coloured product.

EFFECT: method enables to differentiate the cellular component and biofilm matrix, while reducing the analysis time.

1 cl, 3 ex