A composition for stable storage of nucleic acid and polypeptide molecules in a biological sample, comprising: (a) one or more compounds of formula: where: A is -C(R 4)=C(R 4)- or -C(R 4)=C(R 4)-C(R 4) 2 -; Y is N, S or O; R 1 is, when Y is N, C 1 -C 16 alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl or optionally substituted heterocyclylalkyl, and when Y is S or O, R 1 is absent; R 2 is hydrogen, C 1 -C 16 alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl or optionally substituted heterocyclylalkyl; R 3 is C 1 -C 16 alkyl, optionally substituted aryl or optionally substituted aralkyl; each R 4 is independently hydrogen, cyano, nitro, -C OR 5, -C N(R 5) 2, -N(R 5) 2, halo, haloalkyl, hydroxy, alkyl, alkoxy, haloalkoxy, alkoxyalkyl, alkenyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl or optionally substituted heteroarylalkyl; or two adjacent R 4 's, together with the carbons to which they are attached, may form an optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heterocyclyl or optionally substituted heteroaryl; each R 5 is independently hydrogen, alkyl, aryl or aralkyl; and X is a pharmaceutically acceptable anion; and (b) two or all three of: (i) at least one precipitating agent, (ii) at least one lower alcohol, wherein the lower alcohol is a straight or branched carbon chain alcohol of no more than 8 carbons, and (iii) at least one chaotrope; and wherein the composition comprises a chelating agent and/or a reducing agent. (a) one or more compounds of formula: where: A is -C(R 4)=C(R 4)- or -C(R 4)=C(R 4)-C(R 4) 2 -; Y is N, S or O; R 1 is, when Y is N, C 1 -C 16 alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl or optionally substituted heterocyclylalkyl, and when Y is S or O, R 1 is absent; R 2 is hydrogen, C 1 -C 16 alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl or optionally substituted heterocyclylalkyl; R 3 is C 1 -C 16 alkyl, optionally substituted aryl or optionally substituted aralkyl; each R 4 is independently hydrogen, cyano, nitro, -C OR 5, -C N(R 5) 2, -N(R 5) 2, halo, haloalkyl, hydroxy, alkyl, alkoxy, haloalkoxy, alkoxyalkyl, alkenyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl or optionally substituted heteroarylalkyl; or two adjacent R 4 's, together with the carbons to which they are attached, may form an optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heterocyclyl or optionally substituted heteroaryl; each R 5 is independently hydrogen, alkyl, aryl or aralkyl; and X is a pharmaceutically acceptable anion; and A is -C(R 4)=C(R 4)- or -C(R 4)=C(R 4)-C(R 4) 2 -; Y is N, S or O; R 1 is, when Y is N, C 1 -C 16 alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl or optionally substituted heterocyclylalkyl, and when Y is S or O, R 1 is absent; R 2 is hydrogen, C 1 -C 16 alkyl, alkenyl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl or optionally substituted heterocyclylalkyl; R 3 is C 1 -C 16 alkyl, optionally substituted aryl or optionally substituted aralkyl; each R 4 is independently hydrogen, cyano, nitro, -C OR 5, -C N(R 5) 2, -N(R 5) 2, halo, haloalkyl, hydroxy, alkyl, alkoxy, haloalkoxy, alkoxyalkyl, alkenyl, optionally substituted aryl, optionally substituted aralkyl, optionally substituted cycloalkyl, optionally substituted cycloalkylalkyl, optionally substituted heterocyclyl, optionally substituted heterocyclylalkyl, optionally substituted heteroaryl or optionally substituted heteroarylalkyl; or two adjacent R 4 's, together with the carbons to which they are attached, may form an optionally substituted cycloalkyl, optionally substituted aryl, optionally substituted heterocyclyl or optionally substituted heteroaryl; each R 5 is independently hydrogen, alkyl, aryl or aralkyl; and X is a pharmaceutically acceptable anion; and (b) two or all three of: (i) at least one precipitating agent, (ii) at least one lower alcohol, wherein the lower alcohol is a straight or branched carbon chain alcohol of no more than 8 carbons, and (iii) at least one chaotrope; and wherein the composition comprises a chelating agent and/or a reducing agent. (i) at least one precipitating agent, (ii) at least one lower alcohol, wherein the lower alcohol is a straight or branched carbon chain alcohol of no more than 8 carbons, and (iii) at least one chaotrope; and wherein