Cavity Slide – Single, Double and Triple

Quick Answer: The Cavity Slide – Single, Double and Triple is a glass microscope slide with one, two or three shallow ground depressions, used to hold a drop of liquid with living organisms for observation and to make hanging drop preparations.

What the Depressions Are For

On a flat slide, a drop of pond water or culture is squeezed into a thin film under the coverslip, which crushes larger organisms and dries out quickly. Here a shallow concave well is ground into the glass, so the drop keeps some depth. Paramecium, rotifers, Daphnia and mosquito larvae can then move freely while being watched, and the drop lasts longer before it evaporates.

The well also makes the hanging drop technique possible. A drop of bacterial culture is placed on a coverslip, a ring of petroleum jelly is spread round the depression, and the slide is inverted onto the coverslip so the drop hangs into the well without touching the glass. Motile bacteria can then be seen moving without being fixed or stained.

A single well is the usual choice for one sample. Double and triple versions allow side-by-side comparisons on one slide, such as a culture before and after a treatment, or pond samples from three sites. For a thicker slide with a deeper well, see the thick glass concavity slides; both types are used with glass coverslips.

Live-Mount Work

• Observing Paramecium, Euglena, rotifers and other pond organisms alive.
• Hanging drop preparations to check bacterial motility.
• Comparing two or three samples on one slide in ecology and microbiology practicals.
• Watching small crustaceans, larvae or germinating pollen grains in a drop of liquid.

Care & Handling

• Hold the slide by its edges, and lower coverslips with a needle or forceps to avoid trapping air.
• Clean the wells with a cotton bud and detergent; abrasive powders dull the ground surface.
• Disinfect slides used with bacterial cultures before washing, as the lab’s procedure requires.
• Store the slides in a slide box, separated so the wells do not scratch one another.

Specifications

Why Choose LabEquip

Biology teachers, microbiology practical classes and colleges teaching protozoology buy these slides alongside plain slides, since live-mount work needs both. LabEquip lists them in General Lab Products, and mixed orders of single, double and triple well slides can be arranged through the contact page.

Frequently Asked Questions

What is the difference between single, double and triple versions?

The number of wells. The single version holds one sample, while double and triple versions hold two or three separate drops on one slide, which helps when samples need to be compared side by side under the same conditions.

How do I make a hanging drop preparation?

Put a small drop of culture on a clean coverslip and spread a thin ring of petroleum jelly around the well of the slide. Invert the slide onto the coverslip, press gently and turn it over so the drop hangs into the well. Focus on the edge of the drop first.

Why use a slide with a well for pond organisms?

A plain slide flattens the drop under the coverslip, which can crush or trap larger organisms. The well holds a deeper drop, so organisms swim naturally and the preparation stays wet for longer.

Do I need a coverslip over the well?

For live observation at higher magnifications, yes. The coverslip flattens the top of the drop, slows evaporation and keeps liquid off the objective lens. At low power a drop can be viewed uncovered for a short time.

Can these slides be reused?

Yes. Wash them with detergent and warm water, rinse well and dry them with a lint-free cloth. Slides used for bacterial cultures should be disinfected or autoclaved first, following your lab’s biosafety rules.

Why do organisms drift out of focus in the well?

The drop in a well is deeper than a flat film, so organisms swim at different heights. Use the fine focus continuously to follow them, and start at low power, where the depth of field is greater.

Last Updated: September 2026