Urine preservative reagent for microfiltration

Abstract

A preservative reagent for urine is disclosed that increases the stability of cells, such as tumor cells, in urine for a period of several weeks. The preservative reagent comprises polyethylene glycol (PEG), ethanol, paraformaldehyde (PFA), and ethylenediaminetetraacetic acid (EDTA), and optionally pH stabilizing reagents.

What is claimed is: 
     
         1 . A preservative reagent comprising a mixture of 0.2-20% polyethylene glycol (PEG), 25-75% ethanol, 0.04-4% paraformaldehyde (PFA), and 2-200 mM ethylenediaminetetraacetic acid (EDTA). 
     
     
         2 . The preservative reagent of  claim 1 , further comprising one or more pH stabilizing reagents. 
     
     
         3 . The preservative reagent of  claim 2 , wherein the pH of the reagent is in a range of pH 4.0-10.0. 
     
     
         4 . The preservative reagent of  claim 2 , wherein the pH of the reagent is in a range of pH 7.3-7.5. 
     
     
         5 . The preservative reagent of  claim 2 , wherein the pH of the reagent is pH 7.4. 
     
     
         6 . A preservative reagent comprising a mixture of 0.5-5% PEG, 40-60% ethanol, 0.01-2% PFA, and 5-50 mM EDTA. 
     
     
         7 . The preservative reagent of  claim 6 , further comprising one or more pH stabilizing reagents. 
     
     
         8 . The preservative reagent of  claim 7 , wherein the pH of the reagent is in a range of pH 4.0-10.0. 
     
     
         9 . The preservative reagent of  claim 7 , wherein the pH of the reagent is in a range of pH 7.3-7.5. 
     
     
         10 . The preservative reagent of  claim 7 , wherein the pH of the reagent is pH 7.4. 
     
     
         11 . A method for preparing a preserved urine sample comprising adding a preservative reagent of  claim 1  to urine, wherein the ratio of the preservative reagent to urine in the sample is from about 0.1:20 to about 10:0.2 (vol:vol). 
     
     
         12 . The method of  claim 11 , wherein the ratio of the preservative reagent to urine in the sample is from about 0.5:4 to about 2:1 (vol:vol). 
     
     
         13 . The method of  claim 11 , wherein the ratio of the preservative reagent to urine in the sample is about 1:2 (vol:vol). 
     
     
         14 . A method for preparing a preserved urine sample comprising adding a preservative reagent of  claim 6  to urine, wherein the ratio of the preservative reagent to urine in the sample is from about 0.1:20 to about 10:0.2 (vol:vol). 
     
     
         15 . The method of  claim 14 , wherein the ratio of the preservative reagent to urine in the sample is from about 0.5:4 to about 2:1 (vol:vol). 
     
     
         16 . The method of  claim 14 , wherein the ratio of the preservative reagent to urine in the sample is about 1:2 (vol:vol). 
     
     
         17 . A method of collecting cells from a preserved urine sample, comprising
 (a) preparing a preserved urine sample by adding a preservative reagent of  claim 1  to urine, wherein the ratio of the preservative reagent to urine in the sample is from about 0.1:20 to about 10:0.2 (vol:vol), and   (b) collecting cells from the preserved urine sample of (a).   
     
     
         18 . The method of  claim 17 , wherein the cells are collected using one or more of an antibody attached to a solid support, an aptamer attached to a solid support, and a filter. 
     
     
         19 . A method of collecting cells from a preserved urine sample, comprising
 (a) preparing a preserved urine sample by adding a preservative reagent of  claim 6  to urine, wherein the ratio of the preservative reagent to urine in the sample is from about 0.1:20 to about 10:0.2 (vol:vol), and   (b) collecting cells from the preserved urine sample of (a).   
     
     
         20 . The method of  claim 19 , wherein the cells are collected using one or more of an antibody attached to a solid support, an aptamer attached to a solid support, and a filter.