Immunoprobe Localization by Correlative Microscopy: How Much Resolution is Enough?

Extract

With the advent of new ways to image biological material, to tag biological molecules, and to prepare samples, much progress has been made in understanding cellular and subcellular function without resorting to classical electron microscopy. Newer ways to image include the use of microscopies such as: differential interference, video, confocal, near field scanning optical, and magnetic resonance imaging. The use of tags such as cell-permeant organelle-specific markers and green fluorescent protein has further increased our ability to vision subcellular events in living cells, providing us with functional correlations of gene activity and cellular function in a number of biological systems. Techniques such as high pressure freezing coupled with freeze substitution have expanded the range of tissues and organisms that can be optimally preserved and are changing our understanding of cellular fine structure. However, even when electron microscopy is mandated, 1-2 angstrom resolution is rarely indicated except for investigations of molecular structure.