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US 11,306,344 B2Granted
Spectral intensity ratio (SIR) analysis for rapid live microbial enumeration
AssigneeTacount Exact Ltd.
InventorEran Zahavy
Life of this patent
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Abstract
Single dye fluorescent staining (with a membrane-associated dye such as FM 1-43 or FM 4-64) and the combination of differences in both intensity and spectral emission discriminate live from inactivated/dead bacteria and provides for rapid and accurate detection of live bacteria in mixed populations.
Claims10
A method of differentiating between live and inactivated bacteria in a treated sample comprising:
- staining the sample with a N-(3-Triethylammoniumpropyl)-4-(4-(Dibutylamino) Styryl) Pyridinium Dibromide dye;
- illuminating the sample with an incident light at an excitation wavelength of 488 nm, wherein an illuminated live bacteria stained with the N-(3-Triethylammoniumpropyl)-4-(4-(Dibutylamino) Styryl) Pyridinium Dibromide dye exhibits a first maximum emission peak, and wherein an illuminated inactivated bacteria stained with the N-(3-Triethylammoniumpropyl)-4-(4-(Dibutylamino) Styryl) Pyridinium Dibromide dye exhibits a second maximum emission peak that is shifted compared to the first maximum emission peak;
- measuring, for each bacterial cell (i) the intensity I1 of emitted light at wavelength 1 of 530 nm and (ii) the intensity I2 of emitted light at wavelength 2 of 610 nm;
- calculating a ratio I2/I1;
- and
- determining that a bacterial cell is live when I2/I1<2.0 and determining that the bacterial cell is inactivated when I2/I1>2.0.
3 more elements
A method of differentiating between live and inactivated bacteria in a treated sample comprising:
- staining the sample with a N-(3-Triethylammoniumpropyl)-4-(6-(4-(Diethylamino) Phenyl) Hexatrienyl) Pyridinium Dibromide dye;
- illuminating the sample with an incident light at excitation between 488 and 570 nm, wherein an illuminated live bacteria stained with the N-(3-Triethylammoniumpropyl)-4-(6-(4-(Diethylamino) Phenyl) Hexatrienyl) Pyridinium Dibromide dye exhibits a first maximum emission peak, and wherein an illuminated inactivated bacteria stained with the N-(3-Triethylammoniumpropyl)-4-(6-(4-(Diethylamino) Phenyl) Hexatrienyl) Pyridinium Dibromide dye exhibits a second maximum emission peak that is shifted compared to the first maximum emission peak;
- measuring, for each bacterial cell (i) the intensity 11 of emitted light at wavelength 1 of 670 nm and (ii) the intensity I2 of emitted light at wavelength 2 of 780 nm;
- calculating a ratio I2/I1;
- and
- determining that a bacterial cell is live when I2/I1<2.0 and determining that the bacterial cell is inactivated when I2/I1>2.0.
3 more elements
Dependencies are inferred from the claim text.