Abstract: The present invention relates to a temperature-stable labeling reagent of formula: in which R1 represents H or an alkyl, aryl or substituted aryl group, R2 represents a detectable marker or at least two detectable markers linked together by at least one multimeric structure, L is a linking arm containing a linear succession of at least two covalent bonds and n an integer equal to 0 or 1, R3 and R4 represent independently of each other: H, NO2, Cl, Br, F, I, R2-(L)n-Y—X—, OR, SR, NR2, R, NHCOR, CONHR, COOR with R=alkyl or aryl, A is a linking arm containing at least one covalent double bond allowing conjugation of the diazo functional group with the aromatic ring and u is an integer between 0 and 2, preferably equal to 0 or 1, and —Y—X— represents —CONH—, —NHCO—, —CH2O—, —CH2S—.

Abstract: A single- or double-stranded deoxyribonucleic acid (DNA) is fragmented and labeled by chemically fragmenting the DNA by creating at least one abasic site on the DNA, and attaching a marker to at least one of the fragments by means of a labeling reagent, the reagent covalently and predominantly coupling to at least one phosphate of the fragment. This method can be applied in the field of diagnosis.

Abstract: The present invention relates to a temperature-stable labeling reagent of formula: 1

Abstract: The invention relates to a method for labeling and fragmenting a single- or double-stranded deoxyribonucleic acid (DNA) comprising the following steps: