Abstract: A surfactant of formula (I): A-(L1)a-(CH2)b-(L2)c-X??(I) wherein A is a perfluoropolyether; L1 is CONR?, wherein R? is selected from H and C1-6 alkyl; a is 0 or 1; b is 0 or an integer between 1 and 10; L2 is a linking group; c is 0 or 1; and X is a charged group.

Abstract: A surfactant of formula (I): A-(L1)a-(C2)b-(L2)c-X??(I) wherein A is a perfluoropolyether; L1 is CONR', wherein R? is selected from H and C1-6 alkyl; a is 0 or 1; b is 0 or an integer between 1 and 10; L2 is a linking group; c is 0 or 1; and X is a charged group.

Abstract: The present invention provides a surfactant having a formula selected from the group consisting of: B—((X)x—(CH2)a-A)n(VI), (A-(CH2)a—(X)x—B—(X)x—(CH2)a-A)n (IV), (A-(CH2)a—(X)x—B)n (V), and (B)n—(X)x—(CH2)a-A (VII), wherein A is a perfluoropolyether; a is a positive integer; X is either a covalent bond or a linking group; x is a positive integer; B is a polyalkylene oxide unit; n is a positive integer greater than 1 and, in compounds comprising more than one A, B, X, a and x, each may be the same or different. The present invention also relates to methods of making such surfactants, uses of such surfactants and emulsions comprising such surfactants.

Abstract: We describe instruments, and cartridges therefor, for processing droplets of water in oil-in-water emulsions, the droplets containing biological entities such as cells. In one embodiment a method of such processing comprises: providing a plurality of the entities in a fluid: preparing a droplet from said fluid: determining whether said droplet contains one or more entities of said plurality of entities, or whether said droplet does not contain a said entity; sorting said droplet dependent on an outcome of said determination; and dispensing said sorted droplet into a reservoir, wherein said dispensing comprises: identifying said sorted droplet for dispensing; extracting said sorted droplet from a first fluidic flow path of said fluid by transferring said sorted droplet from said first fluidic flow path into a second fluidic flow path; and ejecting said sorted droplet from said second fluidic flow path into said reservoir by applying pressure to said second fluidic flow path.

Abstract: Instruments and cartridges for processing droplets in emulsions containing biological entities such as cells. A method of such processing comprises providing a plurality of the entities in a fluid; preparing a droplet from the fluid; determining whether the droplet contains one or more entities of said plurality of entities, or whether said droplet does not contain a said entity; sorting said droplet dependent on an outcome of the determination; and dispensing the sorted droplet into a reservoir. The dispensing may comprise identifying and extracting the sorted droplet from a first fluidic flow path of said fluid by transferring the sorted droplet from into a second fluidic flow path and then ejecting the sorted droplet into a reservoir by applying pressure to the second fluidic flow path. The droplet contents may be tracked so that the contents of an individual droplet can be sorted, selectively dispensed, and retrieved.

Abstract: A surfactant of formula (I): A-(L1)a-(C2)b-(L2)c-X ??(I) wherein A is a perfluoropolyether; L1 is CONR', wherein R? is selected from H and C1-6 alkyl; a is 0 or 1; b is 0 or an integer between 1 and 10; L2 is a linking group; c is 0 or 1; and X is a charged group.

Abstract: A method of label-free cell or particle sorting in a microfluidic device includes providing a stream of aqueous droplets in oil in a channel of the microfluidic device, wherein at least some of the droplets include cells or particles and illuminating the stream from a first direction. Then, one detects scattered light from cells or particles within said aqueous droplets in a second direction. Next, one determines a number of the cells or particles in each droplet from the scattered light and sorts the aqueous droplets into differentiated streams. Notably, the refractive index of said oil is modified to closely match a refractive index of the aqueous droplets to reduce light scattered from boundaries of the droplets. A volume of the droplets can also controlled.

Abstract: Instruments and cartridges for processing droplets in emulsions containing biological entities such as cells. A method of such processing comprises providing a plurality of the entities in a fluid; preparing a droplet from the fluid; determining whether the droplet contains one or more entities of said plurality of entities, or whether said droplet does not contain a said entity; sorting said droplet dependent on an outcome of the determination; and dispensing the sorted droplet into a reservoir. The dispensing may comprise identifying and extracting the sorted droplet from a first fluidic flow path of said fluid by transferring the sorted droplet from into a second fluidic flow path and then ejecting the sorted droplet into a reservoir by applying pressure to the second fluidic flow path. The droplet contents may be tracked so that the contents of an individual droplet can be sorted, selectively dispensed, and retrieved.

Abstract: The present invention provides an emulsion for sorting droplets in a microfluidic device, the emulsion comprising: a discontinuous aqueous phase; and a continuous oil phase; wherein said aqueous phase comprises at least one analyte, said oil phase comprises a fluorous oil and a refractive index modifying compound comprising at least one aromatic ring, and the refractive index of said aqueous phase and the refractive index of said oil phase are substantially matched.

Abstract: We describe a method of label-free cell and/or particle sorting in a microfluidic device, the method comprising; providing a stream of aqueous droplets in oil in a channel of said microfluidic device, wherein at least some of said droplets include cells and/or particles illuminating said stream from a first direction; detecting, for example, scattered light from cells and/or particles within said aqueous droplets in a second direction; determining, for example, a number of said cells and/or particles in each droplet from the scattered light; and sorting said aqueous droplets into one of a plurality of differentiated streams responsive to said determined number. The method further comprises modifying a refractive index of said oil to more closely match a refractive index of said aqueous droplets to reduce light scattered from boundaries of said droplets. Optionally a volume of the droplets is also controlled. In embodiments the oil is fluorous oil.

Abstract: The present invention provides an emulsion for sorting droplets in a microfluidic device, the emulsion comprising: a discontinuous aqueous phase; and a continuous oil phase; wherein said aqueous phase comprises at least one analyte, said oil phase comprises a fluorous oil and a refractive index modifying compound comprising at least one aromatic ring, and the refractive index of said aqueous phase and the refractive index of said oil phase are substantially matched.