Droplet-based surface modification and washing

Abstract

The present invention relates to droplet-based surface modification and washing. According to one embodiment, a method of splitting a droplet is provided, the method including providing a droplet microactuator including a droplet including one or more beads and immobilizing at least one of the one or more beads. The method further includes conducting one or more droplet operations to divide the droplet to yield a set of droplets including a droplet including the one or more immobilized beads and a droplet substantially lacking the one or more immobilized beads.

1 - 23 . (canceled) 
     
     
         24 . A system for conducting droplet operations, comprising:
 (a) a droplet microactuator comprising:
 (i) a bottom substrate; and 
 (ii) an array of droplet operations electrodes arranged on the bottom substrate; 
   (b) a processor programmed to control droplet operations on the droplet microactuator; and   (c) a cartridge coupled to the droplet microactuator, the cartridge comprising a self-contained replaceable/removable cartridge for conducting a droplet actuator-based assay.   
     
     
         25 . The system of  claim 24 , wherein the cartridge comprises a means for physically coupling to the droplet microactuator. 
     
     
         26 . The system of  claim 24 , wherein the array comprises an electrical connection for electrically coupling electrodes to external circuitry. 
     
     
         27 . The system of  claim 26 , wherein the electrodes are controlled via the external circuitry by the processor. 
     
     
         28 . The system of  claim 27 , wherein the electrical connection comprises electrodes-processor-cartridge. 
     
     
         29 . The system of  claim 24 , wherein the cartridge lacks electrical components. 
     
     
         30 . The system of  claim 24 , wherein the cartridge comprises a reservoir. 
     
     
         31 . The system of  claim 30 , further comprising:
 (d) a fluid path through which fluid can flow from the reservoir onto the droplet microactuator.   
     
     
         32 . The system of  claim 30 , wherein the reservoir comprises one or more reagents. 
     
     
         33 . The system of  claim 30 , wherein the reservoir comprises a filler fluid. 
     
     
         34 . The system of  claim 33 , wherein the filler fluid comprises an oil. 
     
     
         35 . The system of  claim 30 , wherein the reservoir comprises a sample. 
     
     
         36 . The system of  claim 24 , further comprising:
 (e) an analyzer, comprising a slot for insertion of the droplet microactuator.   
     
     
         37 . The system of  claim 36 , wherein the analyzer comprises a portable device. 
     
     
         38 . The system of  claim 37 , wherein the analyzer comprises a hand-held device. 
     
     
         39 . The system of  claim 37 , wherein the analyzer comprises a tabletop device. 
     
     
         40 . The system of  claim 37 , wherein the analyzer comprises a biological fluid analyzer. 
     
     
         41 . The system of  claim 40 , wherein the biological fluid analyzer comprises a module for conducting biological fluid analysis selected from the group consisting of an amperometric module, a potentiometric module, an optical module, and a conductometric module. 
     
     
         42 . The system of  claim 41 , wherein the biological fluid analyzer comprise at least one reservoir. 
     
     
         43 . The system of  claim 41 , wherein the biological fluid analyzer comprises at least one fluid port.