Reagents for preparing a sample containing biomolecular analytes for capillary electrophoretic separation and methods for making the reagents
First Claim
1. Formamide with a conductivity below 10 micro mho and a pH in the range of about 6 to 8.5.
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Accused Products
Abstract
Formamide with low conductivity and a neutral or slightly basic pH is provided. Such formamide may be used in a sample loading solution for capillary electrophoretic separation of biomolecular analytes to enhance the efficiency of sample injection into the capillary and the intensity of the signal. Formamide of the present invention may be obtained by first purifying the formamide to a conductivity of below 7 micro mho, and then adjusting the pH of the purified formamide with a base to a range of about pH 6.5 to 7.5. The purification may be carried out by first removing the water from the formamide, and then distilling the dried formamide until the conductivity of formamide is below about 7 micro mho.
5 Citations
36 Claims
- 1. Formamide with a conductivity below 10 micro mho and a pH in the range of about 6 to 8.5.
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6. A method of preparing formamide for use in electrophoretic separation of biomolecular analytes, comprising:
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(a) purifying the formamide until the conductivity of the formamide is below about 10 micro mho; and
(b) adjusting the pH of the purified formamide from step (a) to a range of about 6 to 8.5. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15)
(a) removing the water contained in the formamide to produce a formamide that is substantially moisture free; and
(b) distilling the substantially moisture-free formamide to generate a purified formamide with a conductivity that is less than 10 micro mho.
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8. The method of claim 7, wherein in step (a) the formamide is treated with moisture-free molecular sieves for removing the water of the formamide.
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9. The method of claim 7, wherein in step (b) the distilling step is repeated.
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10. The method of claim 9, wherein the purified formamide has a conductivity that is about 4 micro mho.
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11. The method of claim 6, wherein in step (b) the pH of the purified formamide is adjusted by a base.
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12. The method of claim 11, wherein the base is a non-nucleophilic base.
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13. The method of claim 11, wherein the base is an organic tertiary amine.
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14. The method of claim 13, wherein the base is selected from the group consisting of triethyl amine (TEA), Diisopropylethyl amine (DIPEA), and tributyl amine (TBA).
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15. The method of claim 14, wherein the base is TBA.
- 16. A reagent for preparing a sample containing biomolecular analytes for capillary electrophoretic separation, comprising formamide having a conductivity below 10 micro mho and a pH in the range of about 6 to 8.5.
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24. A method for preparing a sample containing biomolecule analytes for capillary electrophoretic separation comprising the steps of:
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(a) providing a reagent comprising formamide having a conductivity below 10 micro mho and a pH in the range of about 6 to 8.5; and
(b) mixing the sample with the reagent prior to the capillary electrophoretic separation of the analytes. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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Specification