Droplet assembly method
The invention relates to a process for moving a droplet from a first location to a second location, which droplet comprises a magnetic material disposed in an aqueous medium. The invention also relates to a droplet assembly comprising a droplet, which droplet comprises a magnetic material disposed in an aqueous medium. Various uses of the droplet assembly are also described.
1. A droplet assembly comprising a plurality of contacting droplets wherein each droplet in said plurality is in contact with at least one other droplet in said plurality, wherein each droplet in said plurality comprises an aqueous medium and an outer layer of amphipathic molecules around a surface of the aqueous medium, and wherein at least one of the plurality of contacting droplets comprises a magnetic material disposed in the aqueous medium; and wherein a bilayer of amphipathic molecules is formed at an interface between contacting droplets in said plurality of contacting droplets.
2. A droplet assembly according to claim 1 wherein the magnetic material comprises a paramagnetic or a superparamagnetic material.
3. A droplet assembly according to claim 1 wherein the magnetic material comprises a metal-containing magnetic bead.
4. A droplet assembly according to claim 3 wherein the magnetic bead contains a paramagnetic or superparamagnetic metal.
5. A droplet assembly according to claim 1 wherein the magnetic material further comprises an organic component.
6. A droplet assembly according to claim 1 wherein a bilayer of amphipathic molecules is formed at an interface between each of the contacting droplets in the plurality of contacting droplets.
7. A droplet assembly according to claim 1 wherein the magnetic material comprises nickel nitrilotriacetate.
8. A droplet assembly according to claim 1 wherein the plurality of contacting droplets comprises three or more droplets.
9. A droplet assembly according to claim 8 wherein the aqueous medium of at least two of said plurality of contacting droplets comprises a membrane protein and the aqueous medium of at least one of said plurality of contacting droplets does not comprise a membrane protein.
10. A droplet assembly according to claim 8 wherein the plurality of contacting droplets comprises four or more droplets.
11. A droplet assembly according to claim 10 wherein the aqueous medium of at least two of said plurality of contacting droplets comprises a membrane protein.
12. A droplet assembly according to claim 1 wherein the plurality of contacting droplets comprises at least two layers of droplets.
13. A droplet assembly according to claim 1 wherein at least one of said plurality of contacting droplets has a volume of less than or equal to 1500 nL.
14. A droplet assembly according to claim 1 wherein said plurality of contacting droplets is a first plurality of contacting droplets and the droplet assembly further comprises a second plurality of contacting droplets wherein each droplet in said second plurality comprises an aqueous medium and an outer layer of amphipathic molecules around a surface of the aqueous medium and wherein each droplet in said second plurality is in contact with at least one other droplet in said second plurality, wherein:
(a) the aqueous medium of the droplets of the first plurality of contacting droplets comprises a membrane protein; and
(b) the aqueous medium of the droplets of the second plurality of contacting droplets does not comprise a membrane protein.
15. A droplet assembly according to claim 1 wherein said plurality of contacting droplets is a first plurality of contacting droplets and the droplet assembly further comprises a second plurality of contacting droplets wherein each droplet in said second plurality comprises an aqueous medium and an outer layer of amphipathic molecules around a surface of the aqueous medium and wherein each droplet in said second plurality is in contact with at least one other droplet in said second plurality, wherein:
(a) the aqueous medium of the droplets of the first plurality of contacting droplets comprises a first concentration of a membrane protein; and
(b) the aqueous medium of the droplets of the second plurality of contacting droplets comprises a second concentration of the membrane protein,
wherein the first concentration is greater than the second concentration.
16. A droplet assembly according to claim 1 wherein said plurality of contacting droplets is a first plurality of contacting droplets and the droplet assembly further comprises a second plurality of contacting droplets wherein each droplet in said second plurality comprises an aqueous medium and an outer layer of amphipathic molecules around a surface of the aqueous medium and wherein each droplet in said second plurality is in contact with at least one other droplet in said second plurality, wherein:
(a) the aqueous medium of the droplets of the first plurality of contacting droplets comprises a concentration of at least 50 ng mL −1 of a membrane protein; and
(b) the aqueous medium of the droplets of the second plurality of contacting droplets comprises a concentration of less than 50 ng mL −1 of the membrane protein.
17. A droplet assembly according to claim 1 wherein said plurality of contacting droplets is a first plurality of contacting droplets and the droplet assembly further comprises a second plurality of contacting droplets wherein each droplet in said second plurality comprises an aqueous medium and an outer layer of amphipathic molecules around a surface of the aqueous medium and wherein each droplet in said second plurality is in contact with at least one other droplet in said second plurality, wherein:
(a) a bilayer of amphipathic molecules is formed at an interface between each of the contacting droplets in the first plurality of contacting droplets and each bilayer between each of the contacting droplets in the first plurality of contacting droplets comprises a membrane protein; and
(b) a bilayer of amphipathic molecules is formed at an interface between each of the contacting droplets in the second plurality of contacting droplets and none of the bilayers between the contacting droplets in the second plurality of contacting droplets comprises the membrane protein.
18. A droplet assembly according to claim 1 wherein said plurality of contacting droplets is a first plurality of contacting droplets and the droplet assembly further comprises a second plurality of contacting droplets wherein each droplet in said second plurality comprises an aqueous medium and an outer layer of amphipathic molecules around a surface of the aqueous medium and wherein each droplet in said second plurality is in contact with at least one other droplet in said second plurality, wherein:
(a) a bilayer of amphipathic molecules is formed at an interface between each of the contacting droplets in the first plurality of contacting droplets and the bilayers between the contacting droplets in the first plurality of contacting droplets comprise a first concentration of a membrane protein; and
(b) a bilayer of amphipathic molecules is formed at an interface between each of the contacting droplets in the second plurality of contacting droplets and the bilayers between the contacting droplets in the second plurality of contacting droplets comprise a second concentration of the membrane protein,
wherein the first concentration is greater than the second concentration.
19. A droplet assembly according to claim 17 , wherein the droplets in the first plurality of contacting droplets are in communication with one another via the membrane proteins.
20. A droplet assembly according to claim 18 , wherein the droplets in the first plurality of contacting droplets are in communication with one another via the membrane proteins and the droplets in the second plurality of contacting droplets are not in communication with one another via the membrane proteins.
21. A droplet assembly according to claim 1 , wherein the bilayer comprises a membrane protein.
22. A droplet assembly according to claim 21 , wherein the membrane protein is a pump, channel, pore, receptor or transporter protein.
23. A droplet assembly according to claim 21 , wherein the membrane protein is an α-hemolysin (αHL) pore protein.