Cytosine biotin-hydrazide

Biotin-hydrazide has been used to biotinylate antibodies at their oxidized carbohydrate residues (O Shanessy et al., 1984, 1987 O Shanessy and Quarles, 1985 Hoffman and O Shannessy, 1988), to modify the low-density lipoprotein (LDL) receptor (Wade et al., 1985), to biotinylate nerve growth factor (NGF) (Rosenberg et al., 1986), and to modify cytosine groups in oligonucleotides to produce probes suitable for hybridization assays (Reisfeld et al., 1987) (Chapter 27, Section 2.3). 

Prepare bisulfite modification solution consisting of 3 M concentration of a diamine (i.e., ethylenediamine), 1M sodium bisulfite, pH 6. The use of the dihydrochloride form of the diamine avoids having to adjust the pH down from the severe alkaline pH of the free-base form. Note The optimum pH for transaminating biotin-hydrazide to cytosine residues using bisulfite is 4.5 (see Section 2.3, this chapter). 

Biotin-Hydrazide Modification of Bisulfite-Activated Cytosine Groups... 

Figure 27.13 Biotin-hydrazide may be incorporated into cytosine bases using a bisulfite-catalyzed transamination reaction.

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