Precise and Stable Labeling of Quantum Dots with Engineered Antibodies
Victor R Mann1, Cassio C S Pedroso1, Bruce E Cohen2,3
1The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Abstract:
Quantum dots (QDs) are ideal probes for quantitative bioimaging but require controlled surface functionalization to be useful for imaging specific receptors or other cellular targets. Antibodies (Ab) offer high affinities and specificities against a range of targets, but methods for synthesizing QD-Ab conjugates may offer little control over stoichiometry, orient Ab incorrectly, or be reversible or denaturing. Here, we describe a protocol using SpyCatcher proteins, which spontaneously form covalent bonds with paired SpyTag peptides, to stably link Ab to QD surfaces with control over stoichiometry and orientation. Protocols for immunolabeling of CdSe/CdS QDs with miniaturized Ab, their characterization, and their use in live cell imaging are presented.
Related Concept Videos
Labeling DNA Probes
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
Immunogold Electron Microscopy
Tagging and Fusion Proteins


