Compositions and methods for liquid mixing assessment

Abstract

Compositions include an aqueous solution of an organic dye of molecular weight in the range of about 300 to about 1,000 and a density-enhancing material. An amount of the density-enhancing material in the aqueous solution is sufficient to achieve a density of about 1.0 to about 1.3 g/mL. The composition has a viscosity of about 3.5 to about 5.0 centipoise. The compositions are useful in assessing the adequacy of a liquid handling mixing device to mix a reaction mixture.

What is claimed is: 
     
         1 . A composition comprising an aqueous solution of an organic dye of molecular weight in the range of about 300 to about 1,000 and a density-enhancing material wherein an amount of the density-enhancing material in the aqueous solution is sufficient to achieve a density of about 1.0 to about 1.3 g/mL and wherein the composition has a viscosity of about 3.5 to about 5.0 centipoise. 
     
     
         2 . The composition according to  claim 1  wherein the organic dye is an aromatic azo dye. 
     
     
         3 . The composition according to  claim 1  wherein the organic dye is a triarylmethane dye. 
     
     
         4 . The composition according to  claim 1  wherein the organic dye is selected from the group consisting of Erioglaucine, Ponceau S, Allura Red, Acid Red, Malachite Green, and Amaranth. 
     
     
         5 . The composition according to  claim 1  wherein the density-enhancing material is a polyhydroxy compound. 
     
     
         6 . The composition according to  claim 1  wherein the density-enhancing material is a polyol, a monosaccharide or a disaccharide. 
     
     
         7 . The composition according to  claim 1  wherein the density-enhancing material is selected from the group consisting of sucrose, fructose, trehalose and a mixture of two or more thereof. 
     
     
         8 . The composition according to  claim 1  further comprising one or both of a buffer and a preservative. 
     
     
         9 . A method of assessing the adequacy of a test mixing device to mix a reaction mixture, the method comprising:
 subjecting a layer of water adjacent a layer of the composition of  claim 1  in a container to mixing using the test mixing device at a predetermined level of intensity and duration and measuring a first absorbance from the mixture at a predetermined wavelength;   subjecting a layer of water adjacent a layer of the composition of  claim 1  in a container to mixing using a control mixing device at a level of intensity and duration that maximizes mixing of the mixture and measuring a second absorbance from the mixture at the predetermined wavelength; and   determining a ratio of the first absorbance to the second absorbance wherein a ratio less that about 1 indicates that the ability of the test mixing device to mix a reaction mixture at the predetermined intensity level and duration is not adequate.   
     
     
         10 . A composition comprising an aqueous solution of an aromatic azo dye of molecular weight in the range of about 300 to about 1,000 and a monosaccharide or disaccharide wherein an amount of monosaccharide or disaccharide in the aqueous solution is sufficient to achieve a density of about 1.1 to about 1.2 g/mL and wherein the composition has a viscosity of about 3.5 to about 5.0 centipoise. 
     
     
         11 . The composition according to  claim 10  wherein the organic dye is a triarylmethane azo dye or a fused aryl ring azo dye. 
     
     
         12 . The composition according to  claim 10  wherein the organic dye is selected from the group consisting of Erioglaucine, Ponceau S, Allura Red, Acid Red, Malachite Green, and Amaranth. 
     
     
         13 . The composition according to  claim 10  wherein the monosaccharide or disaccharide is selected from the group consisting of sucrose, fructose, trehalose and a mixture of two or more thereof. 
     
     
         14 . The composition according to  claim 10  further comprising one or both of a buffer and a preservative. 
     
     
         15 . A method of assessing the adequacy of a test mixing device to mix a reaction mixture, the method comprising:
 subjecting a layer of water above a layer of the composition of  claim 10  in a container to mixing using the test mixing device at a predetermined intensity level and duration and measuring a first absorbance from the mixture at a predetermined wavelength, subjecting a layer of the composition of  claim 10  adjacent a layer of water in a container to mixing using a control mixing device at an intensity level and duration that maximizes mixing of the mixture and measuring a second absorbance from the mixture at the predetermined wavelength; and   determining a ratio of the first absorbance to the second absorbance wherein a ratio outside the range of 0.95 to 1.05 indicates that the ability of the test mixing device to mix a reaction mixture at the predetermined level of intensity and duration is not adequate.   
     
     
         16 . A method of assessing the adequacy of a test mixing device to mix a reaction mixture, the method comprising:
 subjecting a layer of water adjacent a layer of a composition in a container to mixing using the test mixing device at a predetermined intensity level and duration and measuring a first absorbance from the mixture at a predetermined wavelength, wherein the composition comprises an aqueous solution of an aromatic azo dye of molecular weight in the range of about 300 to about 1,000 and a density-enhancing material wherein an amount of density-enhancing material in the aqueous solution is sufficient to achieve a density of about 1.0 to about 1.1 g/mL and wherein the composition has a viscosity of about 3.5 to about 5.0 centipoise   subjecting a layer of water adjacent a layer of the composition in a container to mixing using a control mixing device at an intensity level and duration that maximizes mixing of the mixture and measuring a second absorbance from the mixture at the predetermined wavelength; and   determining a ratio of the first absorbance to the second absorbance, wherein a ratio less that 1±0.05 indicates that the ability of the test mixing device to mix a reaction mixture at the predetermined intensity level and duration is not adequate.   
     
     
         17 . The method according to  claim 16  wherein a ratio less than 0.95 indicates that the ability of the test mixing device to mix a reaction mixture at the predetermined intensity level and duration is not adequate. 
     
     
         18 . The method according to  claim 16  wherein the test mixing device is part of an automated analyzer. 
     
     
         19 . The method according to  claim 16  wherein the density-enhancing material is a monosaccharide or a disaccharide. 
     
     
         20 . The method according to  claim 16  wherein the organic dye is selected from the group consisting of Erioglaucine, Ponceau S, Allura Red, Acid Red, Malachite Green, and Amaranth and the density-enhancing material is selected from the group consisting of sucrose, fructose, trehalose and mixtures of two or more thereof.