Projection Slides 35mm, for Microslide Viewer/Bio Viewer

Quick Answer: The Projection Slides 35mm, for Microslide Viewer/Bio Viewer are 35mm photographic transparencies of biological subjects, made to be looked at in a handheld microslide or bio viewer. 35mm projection slides let pupils study enlarged images of cells and tissues without setting up a microscope.

Photographic Slides for Bio Viewers

A bio viewer is a simple optical viewer: the pupil holds it towards a window or lamp and looks through its lens at small photographic images in a mount. The slides carry photographs, typically photomicrographs of cells, tissues and small organisms, so every pupil sees a sharp, correctly identified example of the structure being taught, with no focusing or lighting to get wrong.

Viewers do not replace microscope work, but they support it. Before a practical, pupils can study a clear image of a stained root tip so they know what dividing cells should look like; afterwards, they can compare their own preparation with the photograph. In rooms with few microscopes, or with younger classes, a set of viewers lets everyone work at once. As 35mm transparencies, the slides can also be shown on a 35mm slide projector for class discussion.

The listing does not name the topics included. Tell us which subjects you teach, such as plant tissues, human histology or microorganisms, and the viewer model you use when you enquire. For real specimens to examine under a microscope, see the prepared slides range.

Applications

• Previewing a structure before a microscope practical
• Revising cells, tissues and microorganisms when microscopes are not available
• Whole-class activities where every pupil has a viewer at the same time
• Projecting a single image to discuss with the class

Care & Handling

• Hold 35mm projection slides by the mount, never by the film, and keep fingerprints off the image area.
• Store slides in their box or a slide wallet, upright and out of sunlight, which fades the dyes over time.
• Keep them dry, because damp storage lets fungus grow on the film surface.
• Remove dust with a soft blower brush rather than a cloth.

Specifications

Why Choose LabEquip

Primary and secondary schools, and teacher-training colleges, buy viewer slides to give every pupil a clear view of microscopic life. The slides are listed in the Microscope & Optics range; send the topics and viewer model you need through the contact page.

Frequently Asked Questions

Are these the same as prepared microscope slides?

No. Prepared microscope slides carry a real stained specimen under a cover glass and are viewed through a microscope. Projection slides carry photographs on film and are viewed in a bio viewer or projector, so they need no focusing or lighting skill.

Which age group are bio viewer slides suited to?

They work well from upper primary to lower secondary, and as revision aids for older pupils. Younger children find a viewer easier than a microscope, because the image is already focused and correctly lit.

Can the slides be projected for the whole class?

Standard 35mm slides in individual mounts can be shown on a 35mm slide projector. Some viewer formats hold several images on one card, which a projector cannot take, so check the format of the slides you receive.

How do pupils use a bio viewer?

Pupils insert the slide, hold the viewer towards a window or lamp and look through the lens. Some viewers have a lever or slot to move between images. A worksheet asking each pupil to draw and label one image keeps the activity focused.

Do the slides fade?

Photographic dyes fade slowly with long exposure to light and heat. Keeping the slides in a closed box and out of sunlight when not in use preserves the colours for many years.

How can viewer slides support microscope practicals?

Show the photograph first so pupils know the target structure, then let them find it on a real preparation. Afterwards, pupils compare their drawing with the photograph and discuss differences in staining and magnification.

Last Updated: September 2026