Text and illustrations
below are excerpts from an article, entitled:
Toolbox for Working With Living Invertebrates by
Toolbox contents >)
to be published in
Proceedings of the Association for Biology Laboratory Education
(ABLE), vol. 26, 2004
IV. Foam-well slides
Purpose of tool:
well slides are made from Foamies, an inexpensive craft product that is
non-toxic, non-absorptive, easy to cut, and quick to assemble. When exposed to
water, the adhesive backing on the foam sheet will not loosen from the plastic
or glass surface to which it is attached. These clear-bottom well slides may be
used with either dissecting or compound microscopes, with or without the benefit
of unbreakable coverslips over the wells. Wells may be made in all shapes,
sizes, and depths. The well slides are particularly useful for viewing small
crustaceans (such as daphnids, amphipods, isopods, brine shrimp), small mollusks
(snails), small insect larvae, and many other small organisms. Slides are
unbreakable and easily cleaned.
Clear, heavy acetate transparency sheets for floor of well slides
[Alternate floor materials: clear plastic lamination sheet, Plexiglass,
clear polycarbonate sheet, or glass slide.]
Foam sheets made of EVA (ethylene vinyl acetate) that are
available in many hobby/craft stores, or craft sections of discount stores.
[Option #1: Darice Foamies white, sticky-back sheet. An on-line source
is: ArtCity.com. Cat. # DRC-114413 specifies white Foamies 9 in x 12 in x 2
mm, 10 pack for $3.97. Sheets 6 mm thick are also available.][Option #2: KIDS
Funky Foam Sticky Back EVA Sheet. Item #10506 at Hobby Lobby stores.]
Hand-held paper punch for making circular or oblong holes
[Alternative: X-Acto knife with new blade for making custom-shaped wells.]
Soft cloth or facial tissue
Assembly and use of this
- Use the pen to mark off 1 in
by 3 in rectangles on the paper backing on a foam sheet. Cut out the rectangles
with a scissors.
- Mark the locations and size
of the desired wells on the paper backing.
- With paper backing still
attached to the foam sheet, use the paper punch to punch two or three round
holes in the sheet. [Alternatively, use an X-Acto blade to cut rectangular
wells by making repeated vertical slicing motions of the blade that extend
completely through the foam and into styrofoam backing or cardboard backing.
Avoid cutting movements that shred the foam.]
- Now, remove the paper
backing and carefully lay the foam rectangle on the clear transparency sheet,
aligning it along the straight edge of the sheet. Repeat steps 1-3 until
several rows of foam rectangles are attached to the transparency sheet.
- Then, turn the transparency
sheet over so that the clear side faces up. Use a soft cloth or tissue to
press down firmly on all surfaces of the transparent sheet so that it
thoroughly adheres to the foam strip and all air bubbles under the sheet are
- Use a plastic pipet (or
stretch pipet, as shown in Figs. 7 and 8) to place the specimen into the well
and to adjust fluid level in the well. If no cover slip is used, the water
level should be about even with the top of the well.
- If a cover slip is desired,
then add enough fluid so that the well is slightly over-filled, creating a
convex meniscus. Then, cover the fluid-filled well with a small rectangular
strip of clear transparency sheet. Press very gently on the cover slip and
tilt the slide sideways to drain off excess water drops. The specimen is now
ready for viewing.
- CAUTION: Make sure that the
microscope light source does not overheat organisms within the well.
- After making observations,
slide the cover slip off the well and use a pipet to flush organisms back into
their original container.
- Wells should be rinsed
thoroughly in distilled water and air-dried.
[Total cost is less than 10
cents per well slide. Estimated assembly time is less than 5 min/unit.]
Figure 9. Assembly steps for foam well slides.