Microscope Activities, 22: Homemade and Commercial Slide Chambers

In the past, Hooke College of Applied Sciences offered a microscopy workshop for middle school and high school science teachers. We thought that these basic microscope techniques would be of interest not only for science teachers, but also for homeschoolers and amateur microscopists. The activities were originally designed for a Boreal/Motic monocular microscope, but the Discussion and Task sections are transferable to most microscopes. You may complete these 36 activities in consecutive order as presented in the original classroom workshop, or skip around to those you find interesting or helpful. We hope you will find these online microscope activities valuable.

Experiment 22: Homemade and Commercial Slide Chambers

Goal

To make and use both homemade and commercially available slide chambers.

Level

Basic

Materials Needed

Well slides; various rings and washers; epoxy or glass cement.

Procedure/Discussion

In addition to using ordinary plain flat microscope slides of glass or plastic, it is often necessary to purchase or make a special chamber to:

• accommodate samples that are too thick for ordinary slides and coverglasses
• allow for so-called “hanging drop” experiments
• prepare and observe mini cultures
• allow for observations throughout life histories
• make systematic reference samples (6) to make aesthetic arrangements of diatoms, foraminiferans, butterfly scales, insect eggs, etc.
• perform microchemical tests, or spot tests
• do blood typing, etc.

Figure 22-1 illustrates a variety of such slide chambers.

Well slides are regular microscope slides, or those up to 3-5 times as thick, that have had one, two, or three concave depressions, or “wells” ground and polished into their surface. Slides 2, 3, and 4 up from the bottom on the left side in the figure illustrate ordinary slide thickness well slides with 3, 2, 1 wells; chambers 3 and 4 from the top left side in the figure illustrate 1- and 2- deep well slides in 5 mm thick slides.

At bottom left in the figure an ordinary slide has had a hole drilled or ground through it, and a coverglass cemented over the hole, to form a 1 mm deep chamber. This special slide was made for use with a pocket microscope, in which the objectives are inverted. Holes in glass such as this can be made by grinding, using a hobbyist’s drill with silicon carbide or emery cone grinder; the grinding is done under running water. Also, carbide tipped masonry bits can be used to drill the holes—these are the same kind used to drill holes in cement, and through ceramic tiles and glass; again, water is the coolant and lubricant. Still another method of drilling holes in glass is to chuck a piece of metal tubing into a drill press, and slowly and carefully lower the tubing into the clamped down glass slide, keeping the tubing edge flooded with a slurry of silicon carbide powder in turpentine.

At far upper left side are two examples of shelves or fences made of plastic or glass epoxied to a slide, and serving as supports for one or two coverglasses.

At far upper right are five examples of various metal rings or washers epoxied to slides; the diameter of the rings is selected to complement the coverglass diameter, here from 10-23 mm.

Below the ring/washer chambers are three examples of commercially available multi-chamber slides. Below those is a seven-place chamber slide made from two layers of cardboard—a black square base piece, and a somewhat smaller beige piece in which seven holes have been punched; the upper punched cardboard is cemented to the black base. This kind of chambered slide is used for making type slides or collections of microfossils, or foraminifera, etc. At bottom right is a preformed black plastic chamber cemented to a slide. This kind of chamber is used for arranged insect eggs, polycistina, butterfly scales, foraminifera, sponge spicules, etc.

On the left side, in the middle are a thick glass slide is which an oval chamber has been ground and polished, and a commercially available molded plastic chamber.

Anna Teetsov, now retired from the McCrone Associates staff, has made very successful chambers by punching holes in square pieces of moleskin—one or two layers, adhesive side down, and covered with plastic wrap, rather than coverglasses.

Task

Using the ideas and examples described above, make slide chambers of several varieties; use them and report on the construction and results.