Method of cleaving DNA

A method of cleaving DNA, which method comprises contacting DNA with a sapphyrin-EDTA conjugate under conditions effective to promote cleavage of the DNA, wherein the sapphyrin-EDTA conjugate has the structure:

• ##STR3## wherein, each of R.sup.1 -R.sup.10 is independently H, alkyl, alkene, alkyne, halide, alkyl halide, hydroxyalkyl, glycol, polyglycol, thiol, alkyl thiol, aminoalkyl, carboxyalkyl, alkoxyalkyl, aryloxyalkyl, alkyloxycarbonyl, aryloxycarbonyl, aidehyde, ether, ketone, carboxylic acid, phosphate, phosphonate, sulfate, phosphate substituted alkyl, phosphonate substituted alkyl, or sulfate substituted alkyl, such that the total number of carbon atoms in each substituent R is less than or equal to 10;
• and
• wherein, at least one of R.sup.1 -R.sup.10 is of the formula (CH.sub.2).sub.n -A-(CH.sub.2).sub.m -EDTA where
• A is CH.sub.2, O, S, NH or NR.sup.11,
• R.sup.11 is alkyl, alkene, alkyne, halide, alkyl halide, hydroxyalkyl, glycol, polyglycol, thiol, alkyl thiol, substituted alkyl, phosphate, phosphonate, sulfate, phosphate substituted alkyl, phosphonate substituted alkyl, sulfate substituted alkyl, COO, CONH, CSNH, CONR.sup.11, and
• each of n and m is independently an integer of less than or equal to 10 or zero.