Analysis of Antibody Staining Patterns Obtained with Striated Myofibrils in Fluorescence Microscopy and Electron Microscopy

Abstract

Antibody staining methods have been used in both fluorescence and electron microscopy to identify the presence and distribution of protein in the myofibril. For fluorescence microscopy, the antibody is tagged with fluorescein and its localization in the myofibril is determined by observing the fluorescence of the conjugate. In electron microscopy an initial attempt is made to use mercury as a tag to identify the localization of the antibody. However, the greatest progress has been made using unlabeled antibody. In the myofibril, using both fluorescence and electron microscopy, it has been possible to obtain information concerning the molecular organization and interactions of some of the myofibrillar proteins being localized. The details of the antibody staining patterns obtained with myofibrils have been interpreted as either contradicting the sliding filament model for muscle contraction or agreeing with it. The myofibrillar proteins which have been studied are myosin, actin, tropomyosin, and troponin. Of these, the most work has been done on myosin. In general glycerinated fibrils have been used for staining. The chapter discusses the use of antibodies for the study of the striated myofibril and general considerations for the interpretation of antibody staining patterns. Analysis of antibody staining patterns in terms of distribution, organization, and interaction of protein molecules in the myofibril is presented in the chapter.