Figure 1.

Bioconjugation of oligonucleotides to Qβ nanoparticles. (a) Synthesis of oligo-modified Qβ conjugates. “CuAAC” = CuSO₄, THPTA, sodium ascorbate, aminoguanidine, 0.1 M potassium phosphate buffer, pH 7.4. Particles were purified by desalting and centrifugal ultrafiltration after the second and third steps. (b) Average calculated density of conjugated oligonucleotides, approximating the VLP as a spherical particle; ^†density at inner surface, using a radius of 14 nm. (c) UV–vis spectroscopy of native VLP conjugates and (d) microfluidic chip-based electrophoretic mobility analysis of denatured VLP conjugates were used to determine the relative quantitation of modified and unmodified subunits. Analysis of native unmodified (black), azide-labeled (gold), or 30-mer-labeled (pink) particles by (e) nondenaturing agarose gel electrophoresis and (f) dynamic light scattering, resulting in the average hydrodynamic radius noted for each particle.