Pipette calibration system
First Claim
1. A method for determining the volume of a vessel using a photometer, comprising the steps of:
- a) positioning a container in a photometer, said container holding a reference solution having maximum absorbance at a first wavelength;
b) measuring the absorbance of said container at said first wavelength and at a second wavelength;
c) calculating the optical pathlength of said container at said second wavelength from the measured absorbances at said first and second wavelengths;
d) introducing an aliquot of a sample solution into said container from a vessel to be calibrated, said sample solution having maximum absorbance at said second wavelength, and mixing said sample solution with said reference solution to form a mixture;
e) measuring the absorbance of said mixture in said container at said second wavelength; and
f) calculating the volume of the aliquot from the absorbance of said mixture and the optical pathlength of said container, the volume of said aliquot representing the volume of the vessel.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and apparatus for accurately determining the volume of a pipette using a photometer. A reagent system for use with the photometer includes a first container holding a reference solution and at least one second container holding a sample solution. A container holding the reference solution having maximum absorbance at a first wavelength is positioned in the photometer. The absorbances of the container at the first wavelength and at a second wavelength are measured. Then the optical pathlength of the container at the second wavelength is calculated from the measured absorbances at the first and second wavelengths. An aliquot of the sample solution is introduced into the container with a pipette to be calibrated. The sample solution has maximum absorbance at the second wavelength. The sample solution is mixed with the reference solution to form a mixture. Then the absorbance of the mixture in the container is measured at the second wavelength. The volume of the aliquot is calculated from the absorbance of the mixture and the optical pathlength of the container. The volume of the aliquot represents the volume of the pipette.
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Citations
30 Claims
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1. A method for determining the volume of a vessel using a photometer, comprising the steps of:
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a) positioning a container in a photometer, said container holding a reference solution having maximum absorbance at a first wavelength; b) measuring the absorbance of said container at said first wavelength and at a second wavelength; c) calculating the optical pathlength of said container at said second wavelength from the measured absorbances at said first and second wavelengths; d) introducing an aliquot of a sample solution into said container from a vessel to be calibrated, said sample solution having maximum absorbance at said second wavelength, and mixing said sample solution with said reference solution to form a mixture; e) measuring the absorbance of said mixture in said container at said second wavelength; and f) calculating the volume of the aliquot from the absorbance of said mixture and the optical pathlength of said container, the volume of said aliquot representing the volume of the vessel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 27)
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11. A system for use with a photometer in determining the volume of a vessel, comprising:
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a first container holding a predetermined volume of a reference solution containing a predetermined concentration of a first light absorping material having maximum absorbence at a first wavelength for positioning in the photometer for determination of the optical pathlength thereof; and a second container holding a sample solution containing a predetermined concentration of a second light absorping material having maximum absorbence at a second wavelength for transfer with a vessel to be calibrated of an aliquot of sample solution from the second container to the first container for measurement of the absorbence of the mixture of reference and sample solutions at the second wavelength and for determination of the volume of the aliquot from the optical pathlength of the first container and the absorbence of the mixture, the volume of the aliquot representing the volume of the vessel. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A system for determining the volume of a vessel, comprising:
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a photometer; a container holding a predetermined volume of a reference solution having maximum absorbance at the first wavelength positioned in said photometer; said photometer including means for measuring the absorbance of said container holding a reference solution at said first wavelength and at a second wavelength; means for calculating the optical pathlength of said container at said second wavelength from the measured absorbances at said first and second wavelengths; said photometer including means for mixing said reference solution with an aliquot of sample solution transferred to said container with a vessel to be calibrated to form a mixture, and means for measuring the absorbance of said mixture at said second wavelength; and means for calculating the volume of the aliquot from the measured absorbance of said mixture and the optical pathlength of said container, the volume of said aliquot representing the volume of said vessel. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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28. A method for measuring the optical pathlength of a container to be used for absorbence measurements at a predetermined wavelength, comprising the steps of:
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positioning a container in a photometer, said container holding a reference solution having maximum absorbence at a first wavelength that is different from the predetermined wavelength; measuring the absorbence of said container at said first wavelength and at said predetermined wavelength; calculating the optical pathlength of said container at said predetermined wavelength from the measured absorbences at said first wavelength and said predetermined wavelength; adding a sample solution to the container and making at least one absorbence measurement of the sample solution in the container at a predetermined wavelength; and removing the container from the photometer and subsequently positioning another container in the photometer and repeating the above-defined steps. - View Dependent Claims (29, 30)
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Specification