Methods of determining methylation of DNA are provided. In one illustrative, but non-limiting embodiment the method comprises i) contacting a biological sample comprising a nucleic acid to a first matrix material comprising a first column or filter where said matrix material binds and/or filters nucleic acids in said sample and thereby purifies the DNA; ii) eluting the bound DNA from the first matrix material and denaturing the DNA to produce eluted denatured DNA; iii) heating the eluted DNA in the presence of bisulfite ions to produce a deaminated nucleic acid; iv) contacting said deaminated nucleic acid to a second matrix material comprising a second column to bind said deaminated nucleic acid to said second matrix material; v) desulphonating the bound deaminated nucleic acid and/or simultaneously eluting and desulphonating the nucleic acid by contacting the deaminated nucleic acid with an alkaline solution to produce a bisulfite converted nucleic acid; vi) eluting said bisulfite converted nucleic acid from said second matrix material; and vii) performing methylation specific PCR and/or nucleic acid sequencing, and/or high resolution melting analysis (HRM) on said bisulfite-converted nucleic acid to determine the methylation of said nucleic acid, wherein at least steps iv) through vi) are performed in a single reaction cartridge.