Stabilized droplets for calibration and testing

Patent metadata

Field	Value
Publication number	US-10240187-B2
Application number	US-201615389116-A
Country	US
Kind code	B2
Filing date	Dec 22, 2016
Priority date	Jun 20, 2012
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

Method of detecting a signal from droplets for instrument calibration. In the method, a calibration standard for a droplet detection instrument may be received. The calibration standard may have been shipped at least one kilometer when received. The calibration standard may include a mixture of first droplets and second droplets. Each of the first and second droplets may be encapsulated by an immiscible carrier liquid and may have a stabilizing droplet skin that is formed by heating and that includes a skin-forming protein. Each the first droplets may contain a fluorescent dye, and each of the second droplets may contain a fluorescent dye. A fluorescence signal may be detected from a plurality of the first and second droplets with a droplet detection instrument. The fluorescence signal may be stronger for the first droplets than the second droplets.

First claim

We claim:

1. A method of detecting a signal from droplets for instrument calibration, the method comprising:
detecting a fluorescence signal from a plurality of first and second droplets of a calibration standard with a droplet detection instrument;
wherein the calibration standard has been shipped at least one kilometer and includes a mixture of first droplets and second droplets, wherein each of the first and second droplets is encapsulated by an immiscible carrier liquid and has a stabilizing droplet skin that is formed by heating and that includes a skin-forming protein, wherein each of the first droplets contains a fluorescent dye and each of the second droplets contains a fluorescent dye, and wherein the fluorescence signal is stronger for the first droplets than the second droplets.

2. The method of claim 1 , the droplet detection instrument being a test droplet detection instrument, further comprising a step of receiving certified values for droplet properties of the calibration standard measured with a reference droplet detection instrument.

3. The method of claim 2 , further comprising a step of determining test values for droplet properties of the calibration standard based on the fluorescence signal detected with the test droplet detection instrument, and a step of comparing the test values to the certified values.

4. The method of claim 1 , wherein the first droplets contain the same fluorescent dye as the second droplets.

5. The method of claim 1 , wherein the first droplets simulate a level of fluorescence for positive droplets and the second droplets simulate a level of fluorescence for negative droplets of a nucleic acid amplification assay performed in droplets.

6. The method of claim 1 , wherein the step of detecting a fluorescence signal includes a step of irradiating the plurality of first and second droplets with excitation light, and a step of detecting light emitted from the plurality of first and second droplets.

7. The method of claim 1 , wherein the mixture of first droplets and second droplets is monodisperse.

Assignees

• Bio Rad Laboratories

Inventors

• Hiddessen Amy L
• Chia Erin R

Classifications

• B01F5/0647

  Operations & Transport · mapped topic

• B01F9/00

  Operations & Transport · mapped topic

• G01N2201/127

  Calibration; base line adjustment; drift compensation · CPC title

• B01L3/502784

  specially adapted for droplet or plug flow, e.g. digital microfluidics · CPC title

• B01L2200/148

  Specific details about calibrations · CPC title