Patent ID: 7943320

Claim:
An unsymmetrical cyanine dye having the Formula I wherein A is wherein X is O or S; R 3 , R 4 , R 5 , R 6 and R 7 are independently hydrogen, halogen, thiol, optionally substituted alkyl, optionally substituted alkoxy, optionally substituted alkenyl, optionally substituted polyalkenyl, optionally substituted alkynyl, optionally substituted polyalkynyl, optionally substituted thioalkyl, optionally substituted aminoalkyl, optionally substituted aryl, optionally substituted heteroaryl and optionally substituted arylalkyl; and further wherein R 3 , and/or R 4 , and/or R 5 , and/or R 6 and/or R 7 carry one or more positive charges such that the sum of the positive charge(s) on R 3 , R 4 , R 5 , R 6 and R 7 is 1,2 or 3.