Abstract: Methods of concentrating beads in a droplet and/or loading beads on a fluidic device are provided, including among other things, a method of concentrating beads in a droplet, the method comprising: (a) providing a droplet actuator comprising: (i) an interior droplet operations volume; and (ii) a reservoir exterior to the interior volume; (iii) a droplet established in a liquid path extending from the reservoir into the interior volume; (b) providing magnetically responsive beads in the portion of the droplet which is in the reservoir; (c) magnetically attracting the magnetically responsive beads through the liquid path into the portion of the droplet which is in the interior volume; and (d) forming a droplet comprising one or more of the magnetically responsive beads in the interior volume.

Abstract: Methods of concentrating beads in a droplet and/or loading beads on a fluidic device are provided, including among other things, a method of concentrating beads in a droplet, the method comprising: (a) providing a droplet actuator comprising: (i) an interior droplet operations volume; and (ii) a reservoir exterior to the interior volume; (iii) a droplet established in a liquid path extending from the reservoir into the interior volume; (b) providing magnetically responsive beads in the portion of the droplet which is in the reservoir; (c) magnetically attracting the magnetically responsive beads through the liquid path into the portion of the droplet which is in the interior volume; and (d) forming a droplet comprising one or more of the magnetically responsive beads in the interior volume.

Abstract: The invention provides droplet actuators and droplet actuator cassettes including reagent storage capabilities, as well as methods of making and using the droplet actuators and cassettes. The invention also provides continuous flow channel elements and techniques for using electrodes to manipulate droplets in flowing streams. The invention also discloses methods of separating compounds on a droplet actuator. Various other aspects of the invention are also disclosed.

Abstract: A droplet actuator comprising: (a) a base substrate comprising electrodes configured for conducting droplet operations on a droplet operations surface thereof; (b) a droplet comprising one or more beads situated on the droplet operations surface; (c) a barrier arranged in relation to the droplet and the electrodes such that a droplet may be transported away from the beads using one or more droplet operations mediated by one or more of the electrodes while transport of the beads is restrained by a barrier.

Abstract: A droplet actuator comprising: (a) a base substrate comprising electrodes configured for conducting droplet operations on a droplet operations surface thereof; (b) a droplet comprising one or more beads situated on the droplet operations surface; (c) a barrier arranged in relation to the droplet and the electrodes such that a droplet may be transported away from the beads using one or more droplet operations mediated by one or more of the electrodes while transport of the beads is restrained by a barrier. Related methods and kits are also provided.

Abstract: The invention relates to a droplet actuator with a substrate comprising electrodes arranged for conducting droplet operations on a droplet operations surface of the substrate; a filler fluid phase in contact with the droplet operations surface at least partially surrounding a droplet phase comprising a droplet arranged on one or more of the electrodes, the droplet comprising: (i) a target substance susceptible to loss from the droplet phase into the filler fluid phase; and (ii) an additive which reduces loss of the target substance to the filler fluid phase relative to a corresponding droplet not comprising the additive. The invention also relates to various compositions and methods.

Abstract: Methods of concentrating beads in a droplet and/or loading beads on a fluidic device are provided, including among other things, a method of concentrating beads in a droplet, the method comprising: (a) providing a droplet actuator comprising: (i) an interior droplet operations volume; and (ii) a reservoir exterior to the interior volume; (iii) a droplet established in a liquid path extending from the reservoir into the interior volume; (b) providing magnetically responsive beads in the portion of the droplet which is in the reservoir; (c) magnetically attracting the magnetically responsive beads through the liquid path into the portion of the droplet which is in the interior volume; and (d) forming a droplet comprising one or more of the magnetically responsive beads in the interior volume.

Abstract: The invention provides droplet actuators and droplet actuator cassettes including reagent storage capabilities, as well as methods of making and using the droplet actuators and cassettes. The invention also provides continuous flow channel elements and techniques for using electrodes to manipulate droplets in flowing streams. The invention also discloses methods of separating compounds on a droplet actuator. Various other aspects of the invention are also disclosed.

Abstract: A droplet actuator comprising: (a) a base substrate comprising electrodes configured for conducting droplet operations on a droplet operations surface thereof; (b) a droplet comprising one or more beads situated on the droplet operations surface; (c) a barrier arranged in relation to the droplet and the electrodes such that a droplet may be transported away from the beads using one or more droplet operations mediated by one or more of the electrodes while transport of the beads is restrained by a barrier. Related methods and kits are also provided.