Hybridization chain reaction enables a unified approach to multiplexed, quantitative, high-resolution immunohistochemistry and in situ hybridization.

RNA in situ hybridization based on the mechanism of the hybridization chain reaction (HCR) enables multiplexed, quantitative, high-resolution RNA imaging in highly autofluorescent samples, including whole-mount vertebrate embryos, thick brain slices and formalin-fixed paraffin-embedded tissue sections. Here, we extend the benefits of one-step, multiplexed, quantitative, isothermal, enzyme-free HCR signal amplification to immunohistochemistry, enabling accurate and precise protein relative quantitation with subcellular resolution in an anatomical context. Moreover, we provide a unified framework for simultaneous quantitative protein and RNA imaging with one-step HCR signal amplification performed for all target proteins and RNAs simultaneously.

A 3-D microfluidic combinatorial cell array.

We present the development of a three-dimensional (3-D) combinatorial cell culture array device featured with integrated three-input, eight-output combinatorial mixer and cell culture chambers. The device is designed for cell-based screening of multiple compounds simultaneously on a microfluidic platform. The final assembled device is composed of a porous membrane integrated in between a Parylene 3-D microfluidic chip and a PDMS microfluidic chip.