Droplet-Based Particle Sorting

Abstract

The present invention relates to droplet-based particle sorting. According to one embodiment, a droplet microactuator is provided and includes: (a) a suspension of particles; and (b) electrodes arranged for conducting droplet operations using droplets comprising particles. A method of transporting a particle is also provided, wherein the method includes providing a droplet comprising the particle and transporting the droplet on a droplet microactuator.

1 .- 49 . (canceled) 
     
     
         50 . A method of providing a droplet comprising a single cell, the method comprising:
 (a) providing a droplet comprising a suspension of cells on an droplet actuator capable of optoelectrowetting-mediated droplet operations, the droplet surrounded by an oil medium;   (b) dispensing from the droplet of (a) to provide a dispensed droplet, wherein the dispensing is optoelectrowetting-mediated;   (c) determining whether the dispensed droplet on the droplet actuator comprises a single cell; and   (d) sorting the dispensed droplet on the droplet actuator based on the results of the determining step using optoelectrowetting-mediated droplet operations.   
     
     
         51 . The method of  claim 50  further comprising repeating steps  50 ( b ),  50 ( c ), and  50 ( d ). 
     
     
         52 . The method of  claim 50  wherein the oil medium is substantially immiscible with the droplets of  50 ( a ) and ( b ). 
     
     
         53 . The method of  claim 50  wherein step  50 ( c ) is achieved by detecting a number of cells in the dispensed droplet based on a property of and/or signal from the dispensed droplet. 
     
     
         54 . The method of  claim 53  wherein the detecting step is achieved using a sensor. 
     
     
         55 . The method of  claim 50 , further wherein a single cell determined to be comprised in the dispensed droplet comprises a target cell type, and wherein step  50 ( c ) further comprises detecting the target cell type of the single cell in the dispensed droplet based on a property of and/or signal detected from the dispensed droplet. 
     
     
         56 . The method of  claim 50  further comprising combining a dispensed droplet determined to comprise a single cell with a separate droplet provided on the droplet actuator to form a combined droplet, wherein the separate droplet comprises a substance which interacts with the single cell. 
     
     
         57 . The method of  claim 56  wherein the substance which may interact with the single cell is selected from the group consisting of: beads, cells, microparticles, nanoparticles, drugs, proteins, peptides, antigens, toxins, and antibodies. 
     
     
         58 . The method of  claim 56  further comprising determining in the combined droplet the presence or quantity of the substance indicative of the single cell's response to the substance. 
     
     
         59 . The method of  claim 58  wherein determining in the combined droplet the presence or quantity of the substance indicative of the single cell's response to the substance comprises conducting an assay comprising optoelectrowetting-mediated droplet operations. 
     
     
         60 . The method of  claim 56  wherein the single cell comprises a T cell. 
     
     
         61 . The method of  claim 50  further comprising determining if the dispensed droplet comprises multiple cells and combining a dispensed droplet determined to comprise multiple cells with the droplet comprising the suspension of cells. 
     
     
         62 . The method of  claim 50  further comprising:
 (a) determining if the dispensed droplet comprises multiple cells; 
 (b) splitting a dispensed droplet determined to comprise multiple cells to yield two or more daughter droplets; and 
 (c) analyzing one or more of the daughter droplets for the presence of a single cell. 
 
     
     
         63 . The method of  claim 50  further comprising:
 (a) determining if the dispensed droplet comprises multiple cells; 
 (b) combining a dispensed droplet determined to comprise multiple cells with a buffer droplet to form a combined droplet; 
 (c) splitting the combined droplet to yield two or more daughter droplets; and 
 (d) analyzing one or more of the daughter droplets for the presence of a single cell. 
 
     
     
         64 . The method of  claim 50  further comprising determining if the dispensed droplet does not contain a single cell and transporting a dispensed droplet determined not to contain a single cell back to the droplet comprising the suspension of cells using optoelectrowetting-mediated droplet operations. 
     
     
         65 . The method of  claim 50  further comprising determining if the dispensed droplet does not contain a single cell and discarding a dispensed droplet determined not to contain a single cell. 
     
     
         66 . The method of  claim 50  wherein step  50 ( c ) comprises detecting if a signal indicative of a presence of a single cell is present in the dispensed droplet. 
     
     
         67 . The method of  claim 66  wherein the signal from a dispensed droplet determined to comprise a single cell comprises a fluorescence from a molecule which binds to the single cell. 
     
     
         68 . The method of  claim 66  wherein the signal from a dispensed droplet determined to comprise a single cell comprises a radioactive signal. 
     
     
         69 . The method of  claim 66  wherein the signal from a dispensed droplet determined to comprise a single cell comprises a visual image. 
     
     
         70 . The method of  claim 50  wherein a dispensed droplet determined to comprise a single cell is transported to an on-droplet microactuator reservoir. 
     
     
         71 . The method of  claim 50  wherein additional droplet operations are conducted on a dispensed droplet determined to comprise a single cell. 
     
     
         72 . The method of  claim 50  wherein a dispensed droplet determined to comprise a single cell is further analyzed.