DNA-Modification of Eukaryotic Cells

A novel bioorthogonal method for the modification of cells with single-stranded DNA oligomers is compared to five alternative methods with respect to labeling efficacy, specificity, and effects on cell viability. The new method is based on oxime ligation of aminooxybiotin to aldehyde groups installed by periodate cleavage of cell-surface glycans, followed by the coupling of preformed DNAstreptavidin conjugates. As compared with two literature-reported methods based on direct coupling of N-hydroxysuccinimidyl (NHS)DNA or NHSbiotinylation as well as with techniques based on strain-promoted alkyne-azide cycloaddition, this method shows the highest labeling densities and is sufficiently mild to avoid cell damage. Functionality of the DNA tags is demonstrated by DNA-directed immobilization on solid substrates and assembly of small cell aggregates.