Microscopic Methods and Techniques in Microbiology

Depth of field refers to the thickness of the plane of focus. With a large depth of field, all of the threads can be in focused at the same time. With a smaller or narrower depth of field, only one thread or a part of one thread can be focused, everything else will be out of focus.

Freeze-fracture or freeze-etch – a preparation method particularly useful for examining lipid membranes and their incorporated proteins in face on view. The fresh tissue or cell suspension is frozen rapidly (cryofixation), then fractured by simply breaking or by using a microtome while maintained at liquid nitrogen temperature. The cold fractured surface (sometimes etched by increasing the temperature to about −100 °C for several minutes to let some ice sublime) is then shadowed with evaporated platinum, or gold at an average angle of 45° in a high vacuum evaporator

Here, 'h’ is the smallest distance between two points. The resolving power of a lens is defined as the smallest distance between two objects, which can be identified as separate images by the aided eye.

The principle of confocal imaging was patented in 1957 by Marvin Minsky.

Microcinematography (time-lapse motion pictures) and video recording used to study of movement of cell constituents during cell division, cell migration and movement of other cell structure within the cell.

Deconvolution – it is a undoing process of convolution. This eliminates distortions and blurring caused by the instrumentation in digital image processing techniques to process, analyse and present images obtained from a microscope.

Yes, the oldest published image, known to have been made with a microscope: 'bees' by Francesco Stelluti was in the year 1630.

Prepared mount or permanent mount is a mounting in which the specimen usually undergoes a complex histological preparation that may involve cutting it into very thin sections with a microtome, fixing it to prevent decay, removing any water contained in it, staining specific parts of it with Canada balsam.

A graticule slide is marked with a grid of lines (for example, a 1 mm grid) that allows the size of objects seen under magnification to be easily estimated and provides reference areas for counting minute objects. E.g. a Neubauer slide for cell counting.

Rheinberg illumination is a special variant of dark field illumination in which transparent, coloured filters are inserted just before the condenser, so that light rays at high aperture are differently coloured than those at low aperture (i.e. the background to the specimen may be blue while the object appears self-luminous red).

A standard microscope slide measures about 75 mm by 25 mm (3″ by 1″) and is about 1 mm thick.

Dark field microscopy has an opaque disc placed underneath the condenser lens, so that only light that is scattered by objects on the slide can reach the eye.

Glycerolis used for temporary mounting media. It is the most used.

Dispersion staining is an optical technique that results in a coloured image of a colourless object. This is an optical staining technique and requires no stains or dyes to produce a coloured effect. There are five different microscope configurations used in the broader technique of dispersion staining. They include brightfield Becke line, oblique, darkfield, phase contrast, and objective stop dispersion staining.

2D and 3D tiling, also known as stitching or creating a panoramic, can now be done with the more advanced digital microscope systems.