Microscope slide

This arrangement allows several slide-mounted objects to be quickly inserted and removed from the microscope, labeled, transported, and stored in appropriate slide cases or folders etc.

The origin of the concept was pieces of ivory or bone, containing specimens held between disks of transparent mica, that would slide into the gap between the stage and the objective.

Slides for specialized applications, such as hemocytometers for cell counting, may have various reservoirs, channels and barriers etched or ground on their upper surface.

[6] Various permanent markings or masks may be printed, sand-blasted, or deposited on the surface by the manufacturer, usually with inert materials such as PTFE.

[5] Slides may have special coatings applied by the manufacturer, e.g. for chemical inertness or enhanced cell adhesion.

A solvent-free sealant that can be used for live cell samples is "valap", a mixture of vaseline, lanolin and paraffin in equal parts.

[10] Using the wrong thickness can result in spherical aberration and a reduction in resolution and image intensity.

In a wet mount, the specimen is placed in a drop of iodine or other liquid held between the slide and the cover slip by surface tension.

This method is commonly used, for example, to view microscopic organisms that grow in pond water or other liquid media, especially lakes.

For pathological and biological research, the specimen usually undergoes a complex histological preparation that involves fixing it to prevent decay, removing any water contained in it, replacing the water with paraffin, cutting it into very thin sections using a microtome, placing the sections on a microscope slide, staining the tissue using various stains to reveal specific tissue components, clearing the tissue to render it transparent and covering it with a coverslip and mounting medium.

Popular mounting media include Permount,[14] and Hoyer's mounting medium and an alternative glycerine jelly [15] Properties of a good mounting medium include having a refractive index close to that of glass (1.518), non-reactivity with the specimen, stability over time without crystallizing, darkening, or changing refractive index, solubility in the medium the specimen was prepared in (either aqueous or non-polar, such as xylene or toluene), and not causing the specimen stain to fade or leach.

A set of standard 75 by 25 mm microscope slides. The white area can be written on to label the slide.
A microscope slide (top) and a cover slip (bottom)
A microscope slide prepared in 1855 containing reference specimens from the inner mucosa of the small intestine of a cholera victim.
Common dimensions of microscope slides (in mm).
Blood smears for pathological examination, an example of wet mount
Microscope slides with prepared, stained, and labeled tissue specimens in a standard 20-slide folder
Slide of 60-year-old holotype specimen of a flatworm ( Lethacotyle fijiensis ) permanently mounted in Canada balsam