Detecting protein aggregation and interaction in live cells: A guide to number and brightness

Methods. 2018 May 1;140-141:172-177. doi: 10.1016/j.ymeth.2017.12.001. Epub 2017 Dec 6.


The possibility to detect and quantify protein-protein interactions with good spatial and temporal resolutions in live cells is crucial in biology. Number and brightness is a powerful approach to detect both protein aggregation/desegregation dynamics and stoichiometry in live cells. Importantly, this technique can be applied in commercial set ups: both camera based and laser scanning microscopes. It provides pixel-by-pixel information on protein oligomeric states. If performed with two colours, the technique can retrieve the stoichiometry of the reaction under study. In this review, we discuss the strengths and weaknesses of the technique, stressing which are the correct acquisition parameters for a given microscope, the main challenges in analysis, and the limitations of the technique.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Image Processing, Computer-Assisted / methods*
  • Intravital Microscopy / instrumentation
  • Intravital Microscopy / methods*
  • Microscopy, Confocal / instrumentation
  • Microscopy, Confocal / methods
  • Photobleaching
  • Protein Aggregates*
  • Protein Interaction Mapping / instrumentation
  • Protein Interaction Mapping / methods*
  • Proteins
  • Software


  • Protein Aggregates
  • Proteins