SUMMARY For the practical biologist applying electron microscopy to the study of biological macromolecules, there are serious problems in obtaining high resolution images showing detail below 2.5–3.0 nm. The limitation in resolution from biological specimens can be attributed to support film thickness and granularity, specimen preparation, irradiation damage, focusing effects and possible contamination in the electron beam. Specimens possessing repeating features can be analysed and averaged by optical diffraction and image reconstruction methods which offer some improvement to the signal to noise ratio. The above problems, with particular reference to irradiation damage, still impose the basic limitation for high resolution applications. When considered together they offer formidable difficulties in practical terms in attempting to make full use of the potential resolving power of modern electron microscopes.

Biological specimen

Granularity

10.1111/j.1365-2818.1973.tb03833.x

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Citations (15)

The structure of parainfluenza 3 virus

Virology (1961)

A. P. Waterson Keith E. Jensen D. A. J. Tyrrell R.W. Horne

10.1016/0042-6822(61)90323-3

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Citations (30)

Negative staining: A brief assessment of current technical benefits, limitations and future possibilities

Micron (1994)

J. Robin Harris R.W. Horne

Stain

Negative stain

Limpet

10.1016/0968-4328(94)90051-5

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Citations (65)

Estructura y función de los virus

R.W. Horne Josep Maria Recasens

Source

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Citations (0)

Chorioretinal biopsy in dogs.

PubMed (1980)

Ian J. Constable D. H. SLATTER R.W. Horne

A simplified practical technique for biopsy of retina and choroid has been developed in dogs. A 270 degree circular scleral flap of 3 mm diameter is raised. The risks of chorioretinal bleeding and vitreous loss are greatly reduced by intravenous mannitol and controlled hyperventilation, with hyperoxygenation and transient, systemic hypotension under general anesthesia. Rreasonable ultrastructural detail was preserved in chorioretinal specimens of 1 mm diameter. Repeat biopsies in the same eye are feasible without significant complications.

Choroid

Posterior pole

Local anesthesia

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Citations (18)