Silicone surfactants for emulsion assays
System, including methods and compositions, for making and using emulsions that include a silicone oil and a silicone surfactant. The emulsions may include aqueous droplets disposed in a continuous phase that includes a silicone oil and a silicone surfactant. The aqueous droplets may contain an analyte, optionally at partial occupancy, and/or a luminescent (e.g., photoluminescent) reporter. An assay of the analyte may be performed with the droplets. In some cases, signals may be detected from the droplets, and a characteristic of the analyte, such as an analyte level or activity, may be determined based on the signals.
1. A composition comprising at least one silicone surfactant having the formula:
the formula
or the formula
wherein
each g is independently 5-200;
each h is independently 1-5;
each i is independently 1-5;
each j is independently 15-50; and
each k is independently 2-100.
2. The composition of claim 1 , wherein the composition is an emulsion of aqueous droplets in a silicone oil phase.
3. The composition of claim 2 , wherein the silicone oil phase includes one or more of octamethyl trisiloxane and a polydimethylsiloxane polymer.
4. The composition of claim 2 , wherein the at least one silicone surfactant is present in the composition at a concentration of 0.1% to 10% in the silicone oil phase.
5. The composition of claim 2 , wherein the aqueous droplets include a photoluminescent reporter.
6. The composition of claim 2 , wherein the aqueous droplets include an analyte that is a nucleic acid.
7. The composition of claim 2 , wherein the silicone oil phase includes octamethyl trisiloxane, cyclopentasiloxane or a trimethylsiloxysilicate at a concentration of about 0.1% to 5%.
8. The composition of claim 7 , wherein the at least one silicone surfactant is present at a concentration of about 0.2% to 5% by weight in the silicone oil phase.