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US 8,183,046 B2Granted
Temperature resistant pH buffers for use at low temperatures
AssigneeThe Board of Trustees of the University of Illinois
InventorsYi Lu, Hee-Jung Hwang, Nathan Sieracki, Dewain Garner
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Abstract
A method for preparing a composition that includes selecting a pH of the composition; selecting a first buffer with a negative temperature coefficient; selecting a second buffer with a positive temperature coefficient; and forming the composition comprising the first buffer and the second buffer. The composition has an average temperature coefficient, ΔpH/ΔT(Ta,Tb)≦1×10−3 pH-unit/K and a ΔpH(Ta,Tb)≦0.31 pH-unit for Ta=4 K and Tb=313 K.
Claims15
A composition made by a method comprising:
- selecting a pH of the composition, the composition having a pH of 6 to 8;
- selecting a first buffer with a negative temperature coefficient, the first buffer comprising HEPES or BisTrisPropane;
- selecting a second buffer with a positive temperature coefficient, the second buffer comprising potassium phosphate;
- and
- forming the composition comprising the first buffer and the second buffer;
- wherein the composition does not comprise a pH-indicator dye,
- the composition has an average temperature coefficient ΔpH/ΔT(Ta,Tb)≦1×10−3 pH-unit/K for Ta=253 K and Tb=273 K, or Ta=273 K and Tb=293 K and
- the HEPES or BisTrisPropane comprises 25-60 mole percent of the sum of the first and second buffers, and potassium phosphate comprises the remainder mole percent of the sum of the first and second buffers.
5 more elements
A solution, comprising:
- a first buffer with a negative temperature coefficient, the first buffer comprising phthalate, acetate, MOPS, Tris, BisTris, BisTrisPropane, HEPES or MES;
- and
- a second buffer with a positive temperature coefficient, the second buffer comprising tartrate, phosphate, or borate;
- wherein the solution has an average temperature coefficient ΔpH/ΔT(Ta,Tb)≦1×10−3 pH-unit/K for Ta=4 K and Tb=313 K, and
- wherein the solution does not comprise a pH-indicator dye.
2 more elements
A buffer system, comprising:
- a first buffer with a positive temperature coefficient;
- and
- a second buffer with a negative temperature coefficient;
- wherein the buffer system has an average temperature coefficient ΔpH/ΔT(Ta,Tb)≦1×10−3 pH-unit/K for Ta=4 K and Tb=313 K, a ΔpH(4 K, 313 K)≦0.31 pH-unit,
- and a buffering capacity of at least 0.01 for the temperature range of 4 K to 313 K,
- wherein the buffer system does not comprise a pH-indicator dye, and
- the buffer system has a buffer concentration of 25 mM to 75 mM.
4 more elements
Dependencies are inferred from the claim text.