Correlative fluorescence and electron microscopy on ultrathin cryosections: Bridging the resolution gap

Microscopy has become increasingly important for analysis of cells and cell function in recent years. This is due in large part to advances in light m icroscopy that facilitate quantitative studies and improve imaging of livin g cells. Analysis of fluorescence signals has often been a key feature in t hese advances. Such studies involve a number of techniques including imagin g of fluorescently labeled proteins in living cells, single-cell physiologi cal experiments using fluorescent indicator probes, and immunofluorescence localization. The importance of fluorescence microscopy notwithstanding, th ere are instances in which electron microscopy provides unique information about cell structure and function. Correlative microscopy in which a fluore scence signal is reconciled with a signal from the electron microscope is a n additional tool that can provide powerful information for cellular analys is. Here we review two different methodologies for correlative fluorescence and electron microscopy using ultrathin cryosections and the advantages at tendant On this approach.