SYSTEMS AND METHODS FOR STABILIZING DROPLETS

• US 20140170665A1
• Filed: 09/04/2013
• Published: 06/19/2014
• Est. Priority Date: 09/05/2012
• Status: Active Grant

• Current Assignee: Bio-Rad Laboratories Incorporated
• Original Assignee: Bio-Rad Laboratories Incorporated
• Inventors: Steenblock, Erin, Hiddessen, Amy L.
• Granted Patent: US 9,328,376 B2
• Time in Patent Office: Days
• US Class Current: 435/6.12
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2300/1822 using Peltier elements
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/502784 specially adapted for droplet or plug flow, e.g. digital microfluidics automatic analysis using a stream of discrete samples in a tube system G01N35/08
• CPC Class Codes: B01L 7/525 with physical movement of samples between temperature zones
• CPC Class Codes: C12Q 1/6806 Preparing nucleic acids for analysis, e.g. for polymerase chain reaction [PCR] assay C12Q1/6804 takes precedence

Abstract

This disclosure provides systems, devices, and methods for sample preparation and/or analysis comprising a droplet generator having a first channel in fluid communication with a carrier fluid reservoir and a second channel in fluid communication with a sample reservoir. The first channel and second channel may meet at an intersection that receives a sample from the sample reservoir and a carrier fluid from the carrier fluid reservoir and generates one or more droplets that flow along a droplet channel to a droplet reservoir. An energy application member in thermal communication with the intersection, at least a portion of the droplet channel, the sample reservoir and/or the carrier fluid reservoir may provide energy to an individual droplet of the one or more droplets, such as at the intersection and/or as the droplet moves along the droplet channel to the droplet reservoir.

Claims

1-101. -101. (canceled)

102. A system for sample preparation and/or analysis, comprising:

a droplet generator comprising a first channel in fluid communication with a carrier fluid reservoir and a second channel in fluid communication with a sample reservoir, said first channel and second channel meeting at an intersection that receives a sample from said sample reservoir and a carrier fluid from said carrier fluid reservoir and generates one or more droplets that flow along a droplet channel to a droplet reservoir; and

an energy application member in thermal communication with (i) said intersection, (ii) at least a portion of said droplet channel, (iii) said carrier fluid reservoir and/or (iv) said sample reservoir, wherein said energy application member transfers energy to an individual droplet of said one or more droplets at said intersection, said carrier fluid reservoir and/or said sample reservoir.

103-135. -135. (canceled)

136. A method for forming a droplet containing a sample to be detected, comprising:

a. generating a droplet at an intersection of a first channel and a second channel, said first channel in fluid communication with a carrier fluid reservoir and said second channel in fluid communication with a sample reservoir, wherein said droplet is generated by bringing a carrier fluid from said carrier fluid reservoir in contact with a sample or sample partition from said sample reservoir at said intersection;

b. flowing said droplet along a droplet channel leading from said intersection to a droplet reservoir; and

c. providing thermal energy to said droplet at said intersection, said carrier fluid reservoir and/or said sample reservoir.

137. The method of claim 136, wherein providing thermal energy to said droplet comprises heating said droplet.

138. The method of claim 136, wherein providing thermal energy to said droplet forms a skin around said droplet.

139. The method of claim 136, wherein thermal energy is provided to said droplet with the aid of an energy application member coupled to said (i) intersection, (ii) at least a portion of said droplet channel, (iii) said carrier fluid reservoir and/or (iv) said sample reservoir.

140. The method of claim 139, wherein said energy application member is coupled to any two of (i)-(iv).

141. The method of claim 139, wherein said energy application member is coupled to any three of (i)-(iv).

142. The method of claim 139, wherein said energy application member is coupled to each of (i)-(iv).

143. The method of claim 139, wherein said energy application member transfers energy to said droplet as the droplet moves along said droplet channel to said droplet reservoir.

144. The method of claim 139, wherein said energy application member comprises one or more resistive heating elements.

145. The method of claim 139, wherein said energy application member comprises one or more thermoelectric devices thermally coupled to said droplet channel.

146. The method of claim 136, wherein said droplet flows along said droplet channel as an emulsion.

147. The method of claim 136, wherein said droplet flows along said droplet channel with the aid of a pressure source.

149. The method of claim 136, further comprising thermally cycling said droplet to induce nucleic acid amplification.

150. The method of claim 136, wherein said sample partition is prepared as a reaction mixture for amplification of a nucleic acid target.

152. The method of claim 136, wherein providing energy to said droplet comprises heating said droplet at said intersection.

154. The method of claim 136, wherein providing thermal energy to said droplet comprises heating said droplet in said droplet channel.

162. The method of claim 136, wherein providing said thermal energy comprises (i) providing a first energy by a first heating element that provides for droplet stabilization and (ii) providing a second energy by a second heating element that initiates or facilitates a reaction within an individual droplet.

164. The method of claim 136, wherein providing thermal energy to said droplet stabilizes said droplet.

165. The method of claim 164, wherein providing thermal energy to said droplet prevents said droplet from coalescing with another droplet.

166. The method of claim 136, wherein (a) further comprises generating a plurality of droplets at said intersection.

148. (canceled)

151. (canceled)

153. (canceled)

155-161. -161. (canceled)

163. (canceled)

167-176. -176. (canceled)

177. A method for forming a droplet containing a sample or sample partition, comprising:

a. generating a droplet at an intersection of a first channel and a second channel, said first channel in fluid communication with a carrier fluid reservoir and said second channel in fluid communication with a sample reservoir, wherein said droplet is generated by bringing a carrier fluid from said carrier fluid reservoir in contact with a sample partition from said sample reservoir at said intersection;

b. flowing said droplet along a droplet channel leading from said intersection to a droplet reservoir; and

c. forming a skin around said droplet at or downstream of said intersection.

181. The method of claim 177, further comprising forming said skin by providing energy to said droplet.

190. The method of claim 177, wherein forming said skin around said droplet stabilizes said droplet.

191. The method of claim 177, wherein forming said skin around said droplet prevents said droplet from coalescing with another droplet.

209. The method of claim 177, wherein (a) further comprises generating a plurality of droplets at said intersection.

210. The method of claim 209, further comprising collecting said droplets in said droplet reservoir, wherein said collected droplets have at most about 67% by volume oil and at most about 33% by volume air.

178-180. -180. (canceled)

182-189. -189. (canceled)

192-198. -198. (canceled)

199. A system for sample preparation and/or analysis, comprising:

a droplet generator having a first channel in fluid communication with a carrier fluid reservoir and a second channel in fluid communication with a sample reservoir, said first channel and second channel meeting at an intersection that receives a sample from said sample reservoir and a carrier fluid from said carrier fluid reservoir and generates one or more droplets that flow along a droplet channel to a droplet reservoir; and

an energy application device coupled to (i) said intersection, (ii) at least a portion of said droplet channel, (iii) said carrier fluid reservoir and/or (iv) said sample reservoir, wherein said energy application device provides energy to form a skin around an individual droplet of said one or more droplets.

205. The system of claim 199, further comprising a computer processor that is programmed to (a) regulate the formation of said one or more droplets by said droplet generator, and/or (b) regulate the application of energy by said energy application device to any one, two, three, or all of (i)-(iv).

200-204. -204. (canceled)

206. An emulsion comprising a plurality of droplets having sample partitions, wherein at least a subset of said droplets are capable of emitting a detectable signal, and wherein said emulsion comprises at most about 70% by volume droplets and at least about 30% by volume oil.

207. The emulsion of claim 206, wherein an individual droplet of said plurality of droplets has a skin.

208. (canceled)

211-217. -217. (canceled)