Detection and quantification of endoplasmic reticulum stress in living cells using the fluorescent compound, Thioflavin T

Biochim Biophys Acta. 2013 Oct;1833(10):2293-301. doi: 10.1016/j.bbamcr.2013.05.020. Epub 2013 Jun 5.


The endoplasmic reticulum (ER) plays a central role in the co- and post-translational modification of many proteins. Disruption of these processes can lead to the accumulation of misfolded proteins in the endoplasmic reticulum - a condition known as endoplasmic reticulum stress. In recent years, the association of endoplasmic reticulum stress with a number of disease pathologies has increased interest in the study of this condition. Current methods to detect endoplasmic reticulum stress are indirect and retrospective. Here we describe a new method to detect and quantify endoplasmic reticulum stress in live cells using Thioflavin T (ThT), a small molecule that exhibits enhanced fluorescence when it binds to protein aggregates. We show that enhanced ThT-fluorescence correlates directly with established indicators of unfolded protein response activation. Furthermore, enhanced ThT-fluorescence can be detected in living cells within 20 min of application of an endoplasmic reticulum stress-inducing agent. ThT is capable of detecting endoplasmic reticulum stress induced by distinctly different conditions and compounds, in different cultured cell types as well as in mouse tissue samples. Pre-treatment with a potent endoplasmic reticulum stress-reducing agent, 4-phenylbutyric acid, mitigates the enhanced ThT signal. This new tool will be useful in future research investigating the role of protein misfolding in the development and/or progression of human diseases.

Keywords: Detection; Endoplasmic reticulum stress; Thioflavin T; Unfolded protein response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzothiazoles
  • Cells, Cultured
  • Embryo, Mammalian / metabolism
  • Embryo, Mammalian / pathology*
  • Endoplasmic Reticulum / metabolism
  • Endoplasmic Reticulum / pathology*
  • Endoplasmic Reticulum Stress
  • Fibroblasts / metabolism
  • Fibroblasts / pathology*
  • Fluorescent Dyes*
  • Hep G2 Cells
  • Humans
  • Immunoblotting
  • Liver / metabolism
  • Liver / pathology*
  • Mice
  • Mice, Knockout
  • Protein Folding
  • Protein Multimerization
  • Thiazoles*
  • Unfolded Protein Response*


  • Benzothiazoles
  • Fluorescent Dyes
  • Thiazoles
  • thioflavin T