Adenine glutaraldehyde

An additional reaction reported for adenine involves the coupling of glutaraldehyde to the 6-amino group (Matthews and Kricka, 1988). However, reaction at this group with electrophilic reagents such as those discussed in Section 2 proceeds more slowly than that possible... 

Autofluorescence of cells often complicates the studies with fluorescence microscopy (especially the application of green fluorescent substances). There are different reasons for the occurrence of this phenomenon (157) (i) the fluorescent pigment lipofuscin, which settles with rising age in the cytoplasm of cells (ii) cell culture medium, which often contains phenol red that increases autofluorescence (iii) endogen substances such as flavin coenzymes [flavin-adenine dinucleotide (FDA), flavin mononucleotide (FMN) absorp-tion/emission 450/515nm], pyridine nucleotides [reduced nicotinamide adenine dinucleotide (NADH) absorption/emission 340/460nm] or porphyrine (iv) substances taken up by cells (as mentioned above filipin) and (v) preparation of the cells fixation with glutaraldehyde increases autofluorescence. 

Gasnier et al. [138] also reported the catalytic determination of reduced nicotinamide adenine dinucleotide (NADH) at very low potentials (-0.25V), with excellent sensitivity and stability by using a G CE modified with PEI functionalized with Do and glutaraldehyde as a linker (PEI-Glu-Do). The presence of Do covalently bonded to PEI promotes hydrophobic x-interactions with the CNT walls conferring better stability and mechanical strength to the dispersion compared with nonmodified PEI. 

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