Combining Qdot Nanotechnology and DNA Nanotechnology for Sensitive Single-Cell Imaging.

Immunohistochemistry (IHC) can provide detailed information about protein expression within the cell microenvironment and is one of the most common techniques in biology and medicine due to the broad availability of highly specific antibodies and well-established bioconjugation methods for modification of these antibodies with chromogens and fluorophores. Despite recent advances in this field, it remains challenging to simultaneously achieve high multiplexing, sensitivity, and throughput in single-cell profiling experiments. Here, the combination of two powerful technologies is reported, quantum dot and signal amplification by exchange reaction (QD-SABER), for sensitive and multiplexed imaging of endogenous proteins. Compared to the conventional IHC process using dye-labeled secondary antibodies (which already has a built-in signal amplification mechanism), QD-SABER provides an additional 7.6-fold signal amplification. In addition, the DNA hybridization-based IHC can be rapidly removed to regenerate the sample for subsequent cycles of immunostaining (>10 cycles), greatly expanding the multiplexing capability.