Biomedical Electron Microscopy

This comprehensive reference illustrates optimal preparation methods in biological electron microscopy compared with common methodological problems. Not only will the basic methodologies of transmission electron microscopy like fixation, microtomy, and microscopy be presented, but the authors also endeavor to illustrate more specialized techniques such as negative staining, autoradiography, cytochemistry, immunoelectron microscopy, and computer-assisted image analysis. Authored by the key leaders in the biological electron microscopy field Illustrates both optimal and suboptimal or artifactual results in a variety of electron microscopy disciplines Introduces students on how to read and interpret electron micrographs

The natural, biological, medical, and related sciences would not be what they are today without the microscope. After the introduction of the optical microscope, a second breakthrough in morphostructural surface analysis occurred in the 1940s with the development of the scanning electron microscope (SEM), which, instead of light (i. e. , photons) and glass lenses, uses electrons and electromagnetic lenses (magnetic coils). Optical and scanning (or transmission) electron microscopes are called “far-field microscopes” because of the long distance between the sample and the point at which the image is obtained in comparison with the wavelengths of the photons or electrons involved. In this case, the image is a diffraction pattern and its resolution is wavelength limited. In 1986, a completely new type of microscopy was proposed, which, without the use of lenses, photons, or electrons, directly explores the sample surface by means of mechanical scanning, thus opening up unexpected possibilities for the morphostructural and mechanical analysis of biological specimens. These new scanning probe microscopes are based on the concept of near-field microscopy, which overcomes the problem of the limited diffraction-related resolution inherent in conventional microscopes. Located in the immediate vicinity of the sample itself (usually within a few nanometers), the probe records the intensity, rather than the interference signal, thus significantly improving resolution. Since the most we- known microscopes of this type operate using atomic forces, they are frequently referred to as atomic force microscopes (AFMs).

In 1939, when the electron optics laboratory of Siemens & Halske Inc. began to manufacture the first electron microscopes, the biological and medical profes sions had an unexpected instrument at their disposal which exceeded the reso lution of the light microscope by more than a hundredfold. The immediate and broad application of this new tool was complicated by the overwhelming prob lems inherent in specimen preparation for the investigation of cellular struc tures. The microtechniques applied in light microscopy were no longer appli cable, since even the thinnest paraffin layers could not be penetrated by electrons. Many competent biological and medical research workers expressed their anxiety that objects in high vacuum would be modified due to complete dehydration and the absorbed electron energy would eventually cause degrada tion to rudimentary carbon backbones. It also seemed questionable as to whether it would be possible to prepare thin sections of approximately 0. 5 11m from heterogeneous biological specimens. Thus one was suddenly in posses sion of a completely unique instrument which, when compared with the light microscope, allowed a 10-100-fold higher resolution, yet a suitable preparation methodology was lacking. This sceptical attitude towards the application of electron microscopy in bi ology and medicine was supported simultaneously by the general opinion of colloid chemists, who postulated that in the submicroscopic region of living structures no stable building blocks existed which could be revealed with this apparatus.

The second volume of the series Manuals in Biomedical Research, this book is aimed to be both a concise introduction to the diverse field of microscopy and a practical guide those who require the use of microscopic for methods in their research. It provides young as well as experienced scientists a state-of-the-art multidisciplinary overview of microscopic techniques, covering all the major microscopy fields in biomedical sciences and showing their application in evaluating samples ranging from molecules to cells and tissues.Microscopy has revolutionized our understanding of biological events. Within the last two decades, microscopic techniques have provided insights into the dynamics of biological processes that regulate such events. Biological discovery, to a large extent, depends on advances in imaging techniques and various microscopic techniques have emerged as central and indispensable tools in the biomedical sciences.The four authors bring with them extensive experiences spanning across disciplines such as Microbiology, Molecular and Cell Biology, Tissue Engineering, Biomedical and Regenerative Medicine and so forth, reinforcing the fact that microscopy has proven useful in countless investigations into the mysteries of life.

The advent of electron microscopes has opened up new vistas in the field of science. The ultrastructural morphological evidence offered by electron microscope to substantiate and support other findings is highly rewarding. This book gives a comprehensive overview of the principle and operations of the electron microscope. Numerous electron micrographs have been provided to acquaint the reader with the appearance of highly magnified features seen through the EM. This book would definitely create “a feel for this subject” particularly among those who want to use this technique for their research work.