Correlative microscopy

Correlative microscopy is a method when for the analysis of the very same cell or tissue area several different methods of light or electron microscopy are used. Usually these methods of analysis are separated by the period of additional preparation. Traditionally, LM and EM observations are carried out in different populations of cells/tissues. In biology, light microscopy (LM) is usually used to study phenomena at a global scale and to look for unique or rare events for their subsequent examination under the electron microscope. This combination provides an opportunity for live imaging with subsequent electron microscopic analysis of the very same sample, which provides the convenience and the velocity of light microscopy with the very high level of resolution of electron microscopy. Unfortunately, observation of living cells under EM is still impossible. The advent of true correlative light-electron microscopy (CLEM) has allowed high-resolution imaging by EM of the very same structure observed by LM. This chapter describes imaging with the help of CLEM. The guidelines presented herein enable researchers to analyze structure of organelles and in particular rare events captured by low-resolution imaging of a population or transient events captured by live light imaging can now also be studied at high resolution by EM.