Sequential super-resolution imaging using DNA strand displacement

We describe a simple new method for super-resolution of imaging of many different structures/proteins in the same cell using a sequential imaging strategy. The simple optical setup needs no spectrometers, beam splitters or channel registration. Briefly, antibodies are pre-conjugated to a ‘protector’ strand of ssDNA. After cellular labeling and before imaging, a complementary ‘template’ strand, which is labeled with the dye, is added to the sample to bind and label the protector. After imaging, a third ‘invader’ ssDNA is introduced that gains a toe-hold on the template, and competes it off the antibody-protector complex. Orthogonal sets of protector\template\invader are used to label different cellular structures. All antibody labeling is done at once, before imaging. Both the template binding and invader action only require about ~ 1 minute, allowing quick progression through the different structures. We demonstrate the concept by performing dSTORM imaging on several different proteins in a single cell. The concept is easily extended to multiple proteins and could be used for other SR techniques such as STED and SIM.