The invention concerns the method of detection of
DNA end(s) in a biological material, comprising the following steps I III and at least one of sub-steps a-h of each of steps I-III: I. PREPARATION OF THE MATERIAL comprising a fixation and / or permeabilization and / or
lysis and / or isolation and / or
fractionation and / or immobilization of the biological material, b. increasing
accessibility of
DNA end(s), c. blocking
nonspecific binding site(s) for molecules type 2-6, in the biological material; H.
PROCESSING OF
DNA END(S) comprising d.): modification of DNA end(s) by chemical or physical
processing followed by binding molecules type 1 to the DNA end(s) by catalytic or noncatalytic means; blocking
nonspecific binding site(s) for molecules type 2-6 in the biological material; III RECOGNITION AND DETECTION OF THE
MODIFIED DNA END(S): incubation of the biological material from step II with at least two molecules type 2 and 3 which bind to the molecules type 1 in a manner that allows steps leading to rolling circle amplification (RCA) reactions, g. detection of DNA end(s) by: i. optionally contacting suitable molecules type 4 and / or 5 with molecules type 2 and 3, wherein the molecules type 4 and / or 5 are conjugated with the oligonucleotides type 1, ii. adding oligonucleotides type 2 and
enzyme ligase to allow hybridization of said added oligonucleotides type 2 to the oligonucleotides type 1 already linked to molecules type 4 and / or 5, or to molecules type 2 and 3 if they are linked to oligonucleotides type 1, and subsequently performing DNA
ligation of oligonucleotides type 2, iii. performing amplification by adding
enzyme polymerase and a solution of nucleotides to allow rolling circle amplification (RCA) reactions, and molecules type 6 to allow subsequent hybridization of molecules type 6 to thus obtained product of RCA reactions, h. detection of molecules type 6; wherein when more than one sub-step a-c of step I is performed then they may occur in any order. The invention concerns also use of
rolling circle replication for marking the presence and position of single DNA end(s) and use above-mentioned method for detection of DNA end(s) in a biological material.