METHOD OF PRODUCING INOCULUM WITH SINGLE NUMBER OF MICROORGANISMS Russian patent published in 2024 - IPC C12Q1/00 

FIELD: microbiology.

SUBSTANCE: invention relates to microbiology and can be used to produce an inoculum with a single number of microorganisms. In contrast to existing methods, preparation of the working inoculum is carried out by performing a series of serial dilutions of the primary inoculum, which is prepared from the working culture using a nephelometer or according to laboratory turbidity standards at concentration of 1*108 CFU/ml. Primary inoculum is further diluted in series of 6 test tubes with 0.9% NaCl solution, where the number of CFU of the final test tube No. 6 will correspond to 1*102 CFU in 1 ml of suspension or 1*101 CFU in 0.1 ml of the suspension. Control of the number of CFU of the working inoculum is carried out by inoculation of its aliquot on 5 Petri dishes with Mueller-Hinton agar (MHA) for bacteria with common nutrient requirements and with addition of 5% mechanically defibrinated horse blood and 20 mg/l β-NAD for bacteria with complex nutritional needs (MHA-P) and subsequent counting of the number of CFU on Petri dishes, with the possibility of controlling the number of inoculum microorganisms with content thereof in range of 2-10 CFU per unit volume: in case there is no growth on plates with a nutrient medium or the number of CFU is less than 2, the series of dilutions is prepared again with a decrease in volume of 0.9% NaCl solution in all test tubes by 0.5 ml; if the number of CFU on the plates is more than 10, the series of dilutions is prepared repeatedly with increasing volume of 0.9% NaCl solution in all test tubes by 0.5 ml.

EFFECT: objective of the invention is to improve the method of producing inoculum with the possibility of controlling the number of microorganisms with content thereof in range of 2-10 CFU per unit volume.

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