What do you use if antibodies are too large for super resolution microscopy? Aptamers. These are small affinity reagents (~ 2 nm!) that interact with their target in the same way as an antibody, but without the hefty backbone attached.
The BioOptics World take on this story:
Recognizing that antibodies are too large to use as labels for super-resolution microscopy, scientists have taken antibodies' target recognition and fluorescent tagging features to create small affinity reagents with a typical molecular size of ~2 nm. Called aptamers, the reagents are generated in exactly the same way as recombinant antibodies are by using phage display technology. They allow scientists to position a fluorescent tag on an affinity molecule close to the binding site, enabling more precise live-cell imaging.
Recognizing that antibodies are too large to use as labels for super-resolution microscopy, scientists have taken antibodies' target recognition and fluorescent tagging features to create small affinity reagents with a typical molecular size of ~2 nm. Called aptamers, the reagents are generated in exactly the same way as recombinant antibodies are by using phage display technology. They allow scientists to position a fluorescent tag on an affinity molecule close to the binding site, enabling more precise live-cell imaging.