Protocol for the purification of DNA recovered from agarose and polyacrylamide gels by anion-exchange chromatography. Fragments of DNA recovered from agarose gels are sometimes poor templates or substrates in subsequent enzymatic reactions. This problem can be solved by binding the DNA to a positively charged matrix, such as DEAE-Sephadex or DEAE-Sephacel, in buffers of low ionic strength. After washing the matrix, the DNA is eluted by raising the strength of the buffer.
