Microscope is an important tool we use to observe the microscopic world, we need “objects” mounted on the slide, so that we can observe the wonderful microscopic world.

Next, we will discuss the different types of microscope slides and slide mounting techniques.

1.Type of slide

1.1Common plain glass slides

Standard slides are usually made of glass, size is 1 x 3 inches (25.4 x 76.2 mm).

Cover glass dimensions are 7/8 x 7/8 in. (22 x 22 mm) and thickness is 0.006 in. (0.15 mm). Cover glass is a very thin piece of square glass.

Without a cover glass, surface tension can cause droplets to aggregate into domes. Cover glass can break up this tension, not only flattening the sample, but also allowing very careful examination with minimal focus. The cover glass also prevents the objective from touching the sample droplets.

1.2.Depression or concave slides

A concave slide contains a small hole or indentation in a structure that can hold a liquid similar to water. They’re more expensive.

There are also chambers or cell vials, which allow the cells to be viewed directly, without requiring us to prepare separate slides on the microscope platform. This particularly convenient to cultured cells.

1.3.Microscope camera calibration slide

This type of slide scales an exact length of 1mm for 100 frames, or 0.01mm per frame. This precision stand-type micrometer is used to calibrate a microscope or microscope camera for accurate measurements.

2.Type of mounts

2.1Dry mount

Place the sample directly on the slide. The function of the cover glass is to hold the sample in place and protect the objective lens from direct contact with the sample.

Which samples are suitable for dry packing?

Pollen, hair, feathers or plant material is suitable for dry loading.

2.2 Wet mount

To wet the sample, we suspend the sample with a drop of water between the slide and cover slide. The specific steps are as follows:

l Place a sample on the slide

l Drop one drop of methylene blue or other dyeing solution on the sample (optional)

l Place the edge of the cover glass on the sample and gently lower it at a specific angle.Let one side of the droplet touch the cover glass first.This air can escape from the other side. You can use pliers and toothpicks to guide the microscope cover glass..

l Use Kimwips paper to touch one side of the cover glass to remove any excess solution.

l Super glue (or nail polish) can also be used to seal all edges of cover slides for long-term storage.

What are the samples suitable for wet mount?

Microorganisms from pond water, such as protozoa, algae, paramecium and amoeba, are suitable for wet mount.Cells, such as plant cells, require water tension to prolong peace, including saliva, blood, and urine. Other body fluids used for wet mount.

2.3 Section Mount

To place the slices, the sample must be cut into very thin pieces. A thin cross-section of the plant stem is usually cut with a slice and gently placed on a slide. The stain can be applied directly to the sample before covering it with a coverslip.

What are the samples suitable for section mount

Plants stems, roots and leaves. The solid, which can be cut into small pieces, is also suitable for mounting on parts. Very useful for various samples.

2.4 Smear

Smears are formed by carefully applying a thin layer to the glass and must be air dried. Alternatively, you can use an attachment method , such as transporting a slide through the Bunsen burner flame multiple times. Finally, place the glass on the lid.

What specimens are suitable for smears

Bacterial cultures, bacterial colonies and blood.

3.How to choose mounting media

Mounting medium (or mountant) is a medium that contains a sample when imaging under a microscope. If nothing is added, the simplest type of attachment is air.Liquid fasteners are usually used to fix the sample between the cover plate and the glass slide. Mounting media can also adjust the reflectivity of the sample to improve image quality.

In general, mount media for entire mount slides can be divided into water-based mount media and organic solvent-based mount media.

2.1 Water-based mounting media

Water-based sealers such as pure water, phosphate buffered brine (PBS) and 70% glycerine wet sealer are ideal for beginners and general purposes. Water-based sealers are simple and safe to use.

3.2 Organic solvent-based mounting media

The organic solvent-based sealer, such as Canada balsam is ideal for permanent installation of the slide. However, in some samples, prior to applying the binder, it requires additional dehydration and chemical treatment (use of toxic solvents such as toluene and xylene). Some of the samples, you may even be able to shrink or damage in the solvent-based mountants. For these reasons, in the micro-project we recommend the use of water-based mounting media.

How do professional grade specimens made?

1. The specimen is rough cut to the appropriate parts, are placed in the cassette. By the method of placing the sample, determine the “face” of the sections that can be seen under a microscope. Soft animal tissue, by treating with chemicals (including formalin or alcohol) to maintain the cellular structure, there may be additional process is required. These steps are not necessary because plant tissues have cell walls.
2. The sample is embedded in the material, such as wax, called paraffin, the specimen will be hard hard block.
3. A professional rotary microtome.
4. Carefully place the test piece block and section blade (super sharp!)
5. By rotating the drive wheel, the blade will trim the thin portion of the sample block as peeler kitchen. Each section can be reduced to 3 micrometers (1/30! Of thickness of a human hair). A series of sections can be cut like a ribbon. After that, the ribbon will be moved to a water bath for flotation. Is selected good section, it will be transferred to a glass slide.

Depending on the purpose of the specimen, the blank slides were stained with a specific stain, washed, dried, it will be permanently attached with a cover glass. Now you’re ready for the already-created slide.