Methods and kits for extraction of dna

Abstract

Methods and materials are disclosed for use in recovering a biopolymer from a solution. In particular, the invention provides methods for extraction and isolation of nucleic acids from biological materials. The nucleic acids can be separated by forming a stable complex with soluble polysaccharide polymers and magnetic particles, in the presence of detergents and solvent. When the particles are magnetically separated out of the solution, the nucleic acids are separated with them. The nucleic acids can subsequently be released and separated from the particles. The nucleic acid preparation is useful for achieving efficient and accurate results in downstream molecular techniques such as quantification, identification of the source of the nucleic acids, and genotyping.

1 .- 31 . (canceled) 
     
     
         32 . A method of recovering a nucleic acid, comprising the steps of:
 (a) treating a sample comprising the nucleic acid with a starting solution comprising a polymer and detergent, the polymer comprising dextran and the detergent comprising N-lauroyl sarcosine or lauroyl sarcosinate;   (b) applying suspended magnetically attractable particles to the treated sample, the magnetically attractable particles comprising dextran encased magnetite nanoparticles;   (c) forming a non-covalent complex comprising the nucleic acid-polymer-magnetic particle complex; and   (d) applying a magnetic field to separate the nucleic acid-polymer-magnetic particle complex out of the treated sample; and   (e) recovering the nucleic acid from the non-covalent complex by applying a magnetic field.   
     
     
         33 . The method of  claim 32 , wherein the nucleic acid is derived from a sample of biological material comprising one or more of blood, blood stain, saliva, saliva stain, buccal cells, buccal swab, semen, or semen stain. 
     
     
         34 . The method of  claim 32 , wherein the dextran is in the range of 1-5 mg/ml. 
     
     
         35 . The method of  claim 32 , wherein the dextran has a molecular weight of 5,000,000 to 40,000,000. 
     
     
         36 . The method of  claim 32 , wherein the lauroyl sarconsinate is in the range of about 5-15%. 
     
     
         37 . The method of  claim 32 , wherein the dextran encased particles are in the range of about 2-10 mg/ml. 
     
     
         38 . A method of recovering a nucleic acid from a sample, comprising the steps of:
 (a) lysing cells from a sample in a lysis solution, thus forming a lysate comprising the nucleic acid;   (b) treating the lysate with a starting solution comprising a polymer comprising dextran and a detergent comprising N-lauroyl sarcosine or lauroyl sarcosinate;   (c) applying suspended magnetically attractable particles comprising dextran encased magnetite nanoparticles to form a nucleic acid-polymer-particle complex;   (d) forming a non-covalent complex comprising the nucleic acid-polymer-magnetic particle complex;   (e) washing the nucleic acid-polymer-particle complex with a wash solution;   (f) recovering the nucleic acid by applying a magnetic field.   
     
     
         39 . The method of  claim 38 , wherein the dextran is in the range of 1-5 mg/ml. 
     
     
         40 . The method of  claim 38 , wherein the dextran has a molecular weight of 5,000,000 to 40,000,000. 
     
     
         41 . The method of  claim 38 , wherein the lauroyl sarconsinate is in the range of about 5-15%. 
     
     
         42 . The method of  claim 38 , wherein the dextran encased particles are in the range of about 2-10 mg/ml.