Plastic Well Slides

Quick Answer: Plastic well slides are microscope slides moulded with shallow depressions that hold a drop of liquid. They are used to observe living organisms in pond water, hatching brine shrimp and crystals forming from a solution, mainly under a stereo microscope or the low-power objectives of a compound microscope.

Why a Well Instead of a Flat Slide

A drop of pond water on a flat slide is squashed as soon as a cover glass goes on, and larger organisms such as water fleas, rotifers or mosquito larvae are pressed flat or pushed out to the edge. A well gives them depth to swim in. The drop sits in a shallow hollow, keeps its shape, and can be watched for longer because it does not spread and dry as quickly.

Plastic has practical advantages over glass cavity slides for class use: it does not shatter when dropped, and the slides can be handed to every group without worrying about breakage. The trade-offs are optical and chemical. Moulded plastic is less clear than polished glass and scratches more easily, and it can craze or cloud in contact with some solvents. The listing photograph shows slides with several circular wells, which lets students compare samples side by side; the exact number of wells per slide and the pack quantity are not stated in the title.

Because the liquid in a well is deeper than a thin smear, the image is sharpest at low magnification. Plastic well slides therefore work most comfortably with a stereo microscope, a hand lens or the 4x and 10x objectives of a compound microscope; high-power objectives may touch the liquid before they reach focus.

Applications

• Watching live pond organisms such as Daphnia, rotifers and protozoa
• Observing brine shrimp hatching over a lesson
• Growing salt or copper sulfate crystals from a drop of solution and watching them form
• Comparing drops from different samples in neighbouring wells

Care & Handling

• Wash with mild detergent and lukewarm water, rinse, and let the slides air-dry to avoid scratches from cloths.
• Do not heat the slides or pass them through a flame, and test any alcohol or solvent on one slide first.
• Stack slides with a sheet of paper between them to protect the well surfaces.

Specifications

Why Choose LabEquip

Well slides are popular with schools that run pond-life and microscopy lessons for younger students. LabEquip lists them in Biology Lab Products, and they can be covered with micro cover glasses when a flatter view is needed. Tell us your class numbers through the LabEquip contact page.

Frequently Asked Questions

How is a well slide different from a flat slide?

A well slide has a shallow hollow that holds a drop of liquid in place. Living organisms have room to move, and the drop does not spread and dry as quickly. A flat slide suits thin smears and sections.

Should a cover glass be used on a well slide?

It is optional. Without one, organisms can be viewed at low power and picked out with a pipette. With one, lower it from one edge onto a slightly domed drop to avoid trapping air bubbles, and the surface becomes flat for sharper viewing.

Which objectives work with plastic well slides?

Low-power objectives, such as 4x and 10x, and stereo microscopes work well. High-power objectives have a short working distance and may touch the liquid or cover glass before focusing.

Can plastic well slides be reused?

Yes, if they are washed gently and dried after each use. Replace slides once the wells become scratched or cloudy, because the image loses contrast.

Can the slides be heat-fixed or flamed?

No. Plastic softens and distorts with heat. Heat-fixed smears should be made on glass slides.

How long can organisms be kept alive in a well?

Usually for the length of a lesson. The drop slowly evaporates and warms under the lamp, so top it up with pond water from a dropper and switch the lamp off between observations.

Last Updated: September 2026