Rapid micro-immunohistochemistry

Robert D Lovchik,David Taylor,Govind Kaigala

doi:10.1038/s41378-020-00205-2

Abstract

We present a new and versatile implementation of rapid and localized immunohistochemical staining of tissue sections. Immunohistochemistry (IHC) comprises a sequence of specific biochemical reactions and allows the detection of specific proteins in tissue sections. For the rapid implementation of IHC, we fabricated horizontally oriented microfluidic probes (MFPs) with functionally designed apertures to enable square and circular footprints, which we employ to locally expose a tissue to time-optimized sequences of different biochemicals. We show that the two main incubation steps of IHC protocols can be performed on MDAMB468-1510A cell block sections in less than 30 min, compared to incubation times of an hour or more in standard protocols. IHC analysis on the timescale of tens of minutes could potentially be applied during surgery, enabling clinicians to react in more dynamically and efficiently. Furthermore, this rapid IHC implementation along with conservative tissue usage has strong potential for the implementation of multiplexed assays, allowing the exploration of optimal assay conditions with a small amount of tissue to ensure high-quality staining results for the remainder of the sample.

Highlights

Immunohistochemistry (IHC) is a well-established technique to detect the spatial distribution of antigens in tissue sections and is routinely used for tumor analysis in research laboratories and diagnostic centers
We implemented a single step of the μIHC process by locally presenting the primary Ab solution to the tissue with a vertically oriented microfluidic probes (MFPs) head using the basic configuration of an hydrodynamic flow confinement (HFC) formed via two square-shaped apertures
The horizontal arrangement of the new generation of MFP heads provides room for the fluidic routing required for switching between different processing liquids and allows the deliberate shaping of apertures to enable the creation of different shapes of the confined liquids

Summary

Introduction

Immunohistochemistry (IHC) is a well-established technique to detect the spatial distribution of antigens in tissue sections and is routinely used for tumor analysis in research laboratories and diagnostic centers. This method has been used for well over 50 years with limited modifications to the underlying principle, owing to its robustness. It has undergone several innovations in implementation, automation and throughput. The secondary antibody, which helps to amplify the detection signal, is usually polyclonal and conjugated with enzymes that enable subsequent detection of the signal through

Methods

Results

Conclusion