Methods for capture and selective release of nucleic acids using weakly basic polymer and amplification of same

A method for the amplification and detection of a target nucleic acid comprising:

• I) providing a target nucleic acid using the steps of:
• A) at a pH of less than 7, contacting a lysate suspected of containing a target nucleic acid with a water-soluble, weakly basic polymer comprised of recurring units derived by addition polymerization of:
• 1) from about 15 to 100 weight percent of a water-soluble, weakly basic ethylenically unsaturated polymerizable monomer having at least one group which can be protonated at acidic pH and which is selected from the group consisting of aminoalkyl, imidazolyl, isoxazolyl, pyridyl, piperidyl, piperazinyl, pyrazolyl, triazolyl, tetrazolyl, oxadiazolyl, pyridazinyl, pyrimidyl, pyrazinyl, quinolinyl and quinazolinyl,
• 2) from 0 to about 35 weight percent of a nonionic, hydrophilic ethylenically unsaturated polymerizable monomer, and
• 3) from 0 to about 85 weight percent of a nonionic, hydrophobic ethylenically unsaturated polymerizable monomer in an amount sufficient to form a water-insoluble precipitate of said weakly basic polymer with all nucleic acids present in said lysate, including said target nucleic acid,
• B) separating said water-insoluble precipitate from said lysate, and
• C) contacting said precipitate with a base to raise the solution pH to greater than 7, and thereby releasing said nucleic acids, including said target nucleic acid, from said weakly basic polymer,
• said weakly basic polymer comprising recurring units derived by addition polymerization of one or more ethylenically unsaturated polymerizable monomers having an amine group which can be protonated at acidic pH,
• II) amplifying said target nucleic acid present among said released nucleic acids, and
• III) detecting said amplified target nucleic acid.

A test kit for amplification of a target nucleic acid comprising, separately packaged:

• a) an amplification reaction mixture comprising one or more amplification reagents, and
• b) a weakly basic polymer comprised of recurring units derived by addition polymerization of:
• 1) from about 15 to 100 weight percent of a water-soluble, weakly basic ethylenically unsaturated polymerizable monomer having at least one group which can be protonated at acidic pH and which is selected from the group consisting of aminoalkyl, imidazolyl, isoxazolyl, pyridyl, piperidyl, piperazinyl, pyrazolyl, triazolyl, tetrazolyl, oxadiazolyl, pyridazinyl, pyrimidyl, pyrazinyl, quinolinyl and quinazolinyl,
• 2) from 0 to about 35 weight percent of a nonionic, hydrophilic ethylenically unsaturated polymerizable monomer, and
• 3) from 0 to about 85 weight percent of a nonionic, hydrophobic ethylenically unsaturated polymerizable monomer.

A method for the amplification and detection of a target nucleic acid comprising:

• I) lysing cells or virus particles to release a target nucleic acid,
• II) subjecting said target nucleic acid to the steps of:
• A) at a pH of less than 7, contacting said target nucleic acid with a water-soluble, weakly basic polymer comprised of recurring units derived by addition polymerization of:
• 1) from about 15 to 100 weight percent of a water-soluble, weakly basic ethylenically unsaturated polymerizable monomer having at least one group which can be protonated at acidic pH and which is selected from the group consisting of aminoalkyl, imidazolyl, isoxazolyl, pyridyl, piperidyl, piperazinyl, pyrazolyl, triazolyl, tetrazolyl, oxadiazolyl, pyridazinyl, pyrimidyl, pyrazinyl, quinolinyl and quinazolinyl,
• 2) from 0 to about 35 weight percent of a nonionic, hydrophilic ethylenically unsaturated polymerizable monomer, and
• 3) from 0 to about 85 weight percent of a nonionic, hydrophobic ethylenically unsaturated polymerizable monomer in an amount sufficient to form a water-insoluble precipitate of said weakly basic polymer with all nucleic acids present in said lysate, including said target nucleic acid,
• B) separating said water-insoluble precipitate from said lysate, and
• C) contacting said precipitate with a base to raise the solution pH to greater than 7, and thereby releasing said nucleic acids, including said target nucleic acid, from said weakly basic polymer,
• said weakly basic polymer comprising recurring units derived by addition polymerization of one or more ethylenically unsaturated polymerizable monomers having an amine group which can be protonated at acidic pH,
• III) without further adjustment of pH, amplifying said released target nucleic acid, and
• IV) detecting said amplified target nucleic acid.