They are a series of Nanobodies/VHHs that bind to primary antibodies with high affinity and specificity. Currently, Nano Secondary Antibodies against rabbit and mouse IgG are available.
During product development, we exclude nanobodies that cross-react with other species' IgGs. We select only nanobodies with the desired specificity.
Nano Secondary Antibodies do not contain an Fc region and do not bind to Fc receptors; therefore, they have a very low background.
CD's Nano Secondary Antibodies are monovalent and have very high affinity. Hence, they can be simultaneously incubated with the primary antibody. This method saves incubation time and washing steps. Simultaneous incubation also supports: multiplexing, tissue penetration, and cell staining for flow cytometry.
Of course, nano secondary antibodies can also be used according to standard two-step immunostaining protocols.