How to Make an Inexpensive, Easy-to-Use Compound Microscope,

Using Mainly PVC Parts

Chris Stewart and John Giannini*

St. Olaf College, Biology Department, 1520 St. Olaf Avenue, Northfield, MN 55057

*Email: giannini@stolaf.edu

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Introduction

By enabling students to view cells, organelles, and other specimens that would otherwise be

invisible to the human eye, a compound light microscope is a crucial tool for any biology

teaching lab. Unfortunately, the high cost of these instruments (even student models) can

often impose a significant economic burden on many schools – especially if buying a set of 10 to

20 microscopes to cover all of the lab groups in a given course.

Thankfully, a number of educational articles and websites have described various ways to build

inexpensive microscopes for student use as part of a teaching lab or other instructional activity

(Caplan, 2009; Carboni, 2011; Cybulski, Clements, and Prakash, 2014; Drace, Couch, and

Keeling, 2012; Dubowsky, 1996; Mahaffey, 1999; Tsagliotis, 2012; Whibley, 1981). In general,

these sources discuss how to make basic microscopes from supplies that would be available at

most schools or which could be purchased at different types of arts and crafts, hobby, or

hardware stores.

In this same spirit, we explain here how to build a working compound light microscope using

PVC parts, a push-button LED light, inexpensive microscope optics (i.e., an eyepiece and

objective lens), and a few other items that should be available at most schools or which can be

easily purchased at a grocery or hardware store, (e.g., rubber bands, black construction paper,

super glue, etc.).

This design is actually a precursor to a more advanced model that we described in a 2016 article

for The Journal of Chemical Education, which explained how to make a low-cost microscope for

viewing fluorescent cells or other samples (Stewart and Giannini, 2016). We called that

microscope “the OPN Scope” (short for Open Scope) because all of its plans and parts were

designed to be open and accessible to all. That way, others could use or modify the instrument

to fit their own educational or research needs.

Since many of the steps (and several of the parts) for building the microscope described here

are the same as (or similar to) those for making the OPN Scope, we encourage readers to

review the Supporting Information (S4) for our 2016 article, which should be available for free

on the website for The Journal of Chemical Education. The supplement itself describes in detail

how we built a PVC version of the OPN Scope, and we hope that readers will find our

description of the process that we followed there to be helpful.

Finally, to avoid any confusion between the two instruments, we call the microscope described

in this manual the bright-field version of the OPN Scope; and, like other OPN instruments that

we have developed (OPN Lab, 2017), we encourage readers to use or modify this design as

necessary to fit their particular needs.

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The Workings of a Basic Compound Light Microscope

For those unfamiliar with the instrument, a basic compound light microscope contains two

lenses (Fig. 1): one in the eyepiece (called the “ocular lens”) and the other in the objective

(called, not surprisingly, the “objective lens”). The total magnification of the microscope is the

product of the magnification of the ocular and objective lenses. Thus, for example, using a 5x

eyepiece with a 4x objective will generate a total magnification of 20x (since 5 x 4 = 20).

Figure 1. The lenses in a basic compound light microscope.

In addition, in order for the microscope to maintain a proper focus, there must be a specific

fixed distance between the ocular and objective lenses. This distance is called the “tube

length,” and it is typically measured from the “seat” of the eyepiece (Fig. 1, top) to the

“shoulder” of the objective (Fig. 2, arrow pointing left). Often, the objective will even have the

tube length (in mm) printed on it (Fig. 2, arrow pointing right).

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Figure 2. An AM Scope 4x objective, which shows the tube length of 160

mm (arrow pointing right) and “shoulder” or raised ring (arrow pointing

left).

Besides maintaining a fixed distance between the ocular and objective lenses, a microscope

typically has a way to make “coarse” and “fine” adjustments in order to bring a sample into

better focus, and readers can visit any number of websites for more information on the design

and use of microscopes, such as: the Bates College compound microscope web page, the

Celestron PDF manual on microscope basics, or the Nikon “Microscopy U” home page.

Materials

We list the raw materials needed to build this microscope in Table 1 below (along with their

estimated cost at January 2017 prices, not including any taxes or shipping costs). We further

include the total and per unit cost to make seven such microscopes, which is approximately $44

per instrument (again, not including any taxes or shipping costs). Of course, because many

schools may already have several of the supplies needed to build this microscope (e.g., large

plastic weigh boats, black construction paper, rubber bands, super glue, etc.), the cost may be

even lower.

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Table 1. The Parts Needed to Make a Bright-Field Version of the OPN Scope.

Qty Description Unit Price Total Price 1 ¾-inch thick PVC board (5½ inches wide and 8 feet long)

(One board will makes seven microscope bases and PVC disks) $18.00 $18.00

3 ¾-inch thick PVC trim (1½ inches wide and 8 feet long) (Three pieces will make seven sets of support arms and necks)

$5.00 $15.00

1 ¾-inch Schedule 40 (white) PVC pipe (5 feet long) (One pipe will make ten microscope tubes)

$2.00 $2.00

7 ¾-inch Schedule 40 (white) PVC coupling (male adapter) $0.50 $3.50 7 ¾-inch Schedule 80 (dark gray) SPG x SOC bushing $2.00 $14.00 7 3-inch diameter female PVC couplings $3.50 $24.50 7 3-inch diameter male PVC couplings $2.50 $17.50 7 Circular push-button LED lights (less than 3-inch diameters) $2.00 $14.00 4 Sets of two 5x or 10x eyepieces for a compound microscope $18.00 $72.00 7 4x objective lenses for a compound microscope $13.00 $91.00 7 Pieces of black construction paper (3 x 5½ inches) $2.00 $2.00

14 1¼-inch long No. 6 drywall screws (package of 50 screws) $2.00 $2.00 14 Large plastic weight boats (package of 100 available online) $16.00 $16.00 1 Package of large rubber bands $2.00 $2.00 1 Package of sandpaper (60-grit or similar) $1.50 $1.50 1 Bottle of super glue $3.50 $3.50 1 Roll of tape (e.g., masking, labeling, etc.) $1.00 $1.00 1 Roll of electrical tape $1.00 $1.00 1 Package of cork or felt pads $3.00 $3.00 Total Cost: $98.50 $303.50 Cost per Microscope (for 7 models): N/A $43.36

Most of the above items (particularly the PVC board, trim, pipe, and couplings) can be

purchased at any hardware or home improvement store. However, to make the specific PVC

parts for this microscope, readers will need to cut the PVC board, trim, pipe, and couplings to

size (Fig. 3), and we include the dimensions for these various pieces (as well as some basic

instructions for making them) in Table 2 below.

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Figure 3. The supplies needed to build the bright-field version of the OPN Scope

(including the rectangular base, pieces for the microscope arm and neck, the PVC tube

for the lenses, and the circular disk – all of which need to be cut to size).

While some lumber yards or home improve stores may cut some of these pieces for customers

(if the request is a reasonable one), readers may find that they need to cut other pieces (or,

possibly, all of the parts) themselves. If so, many schools often have a wood shop that should

have the appropriate tools. Otherwise, teachers can see if a friend or colleague has a shop at

home, where these pieces could be cut.

Either way, we have found that using a chop saw works much better than a table saw to cut the

pieces of PVC board and trim as well as the PVC pipe and male PVC coupling. However, please

make sure to bring the saw blade down slowly on these pieces (especially the PVC pipe and

coupling) to avoid nicking or cracking these parts. In addition, we have used a band saw to cut

the circular PVC disk and a drill press with a vice bolted to the platform to drill holes into the

PVC disk and female PVC coupling.

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Table 2. Dimensions of the PVC Parts for the Bright-Field Version of the OPN Scope.

PVC Piece Microscope Part Instructions

PVC Board Labeled: 4/4” x 6” x 8’ Actually: ¾” x 5½” x 8’

Rectangular Base (¾ x 5½ x 9 inches)

Cut a 9-inch long piece for the base.

Circular Disk (3½ inch diameter)

Cut a 3½-inch square; drill a ½-inch diameter hole in the center; cut the square into a 3½-inch diameter circle; and sand as necessary until it fits into the top of the male PVC coupling.

PVC Trim Labeled: 4/4” x 2” x 8’ Actually: ¾” x 1 ½” x 8’

Arm (¾ x 1½ x 8½ inches – two) (¾ x 1½ x 10 inches – one)

Cut two 8½-inch long pieces and one 10-inch long piece to make the support arm of the microscope.

Neck (¾ x 1½ x 4 inches – two) (¾ x 1½ x 2 inches – one)

Cut two 4-inch long pieces and one 2-inch long piece to make the neck of the microscope, which will hold the PVC tube for the lenses.

PVC Pipe (¾” x 5’)

Microscope Tube (¾ x 5½ inches)

Cut 5½-inch (~140-mm) long pieces to provide a 160-mm tube length (the additional distance will be provided by the PVC coupling that holds the eyepiece and objective, respectively).

3-inch PVC Coupling (Male)

Adjustable Stage – Top Cut ¾ inches off the top of this piece (or add ¾ inches to the length of the support arm and adjust the diameter of the PVC disk as needed).

3-inch PVC Coupling (Female)

Adjustable Stage – Bottom Drill a 1½-inch diameter hole into the bottom half of this piece, so that students can easily turn on and off the push-button LED light.

Also, as explained in our OPN Scope paper (Stewart and Giannini, 2016), working with power

tools can be extremely dangerous, and the significant physical hazards that they pose should

be obvious. Therefore, any readers who are unfamiliar with these types of tools or how to use

them should work with a trained and experienced craftsperson in order to avoid serious injury.

Readers should also make sure to wear the proper protective equipment when working with

these tools, including any necessary eye and ear protection.

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Readers should further know that, as with the OPN Scope, we recommend using PVC pieces to

make this microscope because, unlike many types of wood, PVC should not warp, split, rot, or

crack over time (especially in places that experience humid summers and dry winters). Also, we

have generally found that warping tends to be the most serious problem. Specifically, if there is

a bow in the rectangular base of the microscope (Cover Image, bottom), then students may find

that the stage “wobbles” a bit, which may cause a “ripple” effect in their images – especially if

using a digital microscope camera to take photographs of their samples.

Of course, PVC board and trim is often much more expensive than wood (especially wood

purchased from the “spare” or “scrap” wood bin at a lumber yard or home improvement store).

As a result, if using wood to help keep costs low, we suggest using plywood for the rectangular

base of the microscope because this type of composite wood may be less likely to warp than

other types of inexpensive wood (e.g., pine). Also, since the arm and neck of the microscope

are made by gluing various pieces of wood together, these pieces are less likely to warp

significantly over time (especially if initially placed in a vice or under a fixed weight to press the

pieces together as the glue dries).

Also, before buying any ¾-inch PVC couplings or bushings to hold the eyepiece and objectives,

we suggest that readers first test out these PVC parts by placing each one of them onto the ¾-

inch PVC pipe that they intend to purchase in order to ensure that the pieces will fit together

smoothly. Otherwise, readers may find that the pipe which they purchased is slightly larger or

smaller than their couplings and bushings. As a result, the ends of each length of PVC pipe

would need to be sanded or wrapped in a few layers of electrical tape (respectively) in order to

provide the appropriate fit.

With respect to the eyepiece and objective lens themselves (Fig. 3, top right), readers can

purchase new or used optics online from websites like Amazon, eBay, or AM Scope or,

alternatively, salvage lenses from any older or broken microscopes that may be at their schools.

For example, in our PVC microscopes, we have successfully tested out new 5x eyepieces (SKU

No. EP5X23H-V299) and 10x eyepieces (SKU No. EP10X23-V299) with 4x objective lenses (SKU

No. A4X-V300) – all manufactured by AM Scope. In addition, we have used 10x eyepieces and

various objectives (4x, 10x, and 40x), which we harvested from a used Carlsan microscope that

we bought on eBay for roughly $15. While both sets of optics required a 160-mm (~6.3-in) tube

length (Figs. 1 and 3), other sets of eyepieces and objectives may require a different fixed

distance. As a result, readers may need to adjust the length of their PVC tubes accordingly.

Also, for simplicity, when buying objective lenses, we recommend selecting ones that have a

raised ring (i.e., shoulder) right below the threads – like the AM Scope 4x objective shown in

Figure 2 above. That way, the objective can fit into the ¾-inch PVC bushing without falling

through the bottom hole.

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Constructing the Microscope

Once all of the PVC pieces have been cut to size, assembling the microscope is rather straight

forward, and we provide the following general instructions (with supporting figures) to assist

readers in completing these steps.

Step 1. First, lay out all the components for the microscope (Fig. 4) and make sure that all of

the parts listed in Table 1 above are present.

Figure 4. The supplies needed to build the bright-field version of the OPN Scope,

including the rectangular base, pieces for the microscope arm and neck, the PVC tube,

and the circular disk – all of which need to be cut to size.

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Step 2. Then, to make the support arm and neck for the microscope (Cover Image, left), align

the longer and shorter 1½ inch wide pieces of PVC trim as shown in Figure 5 below.

Figure 5. The pieces of 1½-inch wide PVC trim needed to make the support arm

(left) and neck (right) to the microscope.

Importantly, when arranging the three smaller pieces for the neck, place the middle piece off-

center to create a 1½-inch long slot on one end of the neck and a ½-inch long slot on the other

end (Fig. 5, lower right). The longer slot will be used to hold the neck to the arm of the

microscope (Cover Image, upper left), and the shorter slot will be used to hold the tube for the

eyepiece and objective in place (Cover Image, upper right).

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Step 3. Next, glue each set of pieces for the arm and neck together with super glue as shown in

Figure 6 below. Make sure to align the pieces correctly at the outset because the glue will dry

quickly once it has been applied.

Figure 6. Gluing the pieces of PVC trim together to make the support arm

(left) and neck (right) for the microscope.

Again, when gluing together the three smaller PVC pieces for the neck, make sure to place the

middle piece off-center, so that it leaves a 1½-inch long slot on one end of the neck and a ½-

inch long slot on the other end (Fig. 6, lower right). The longer slot is needed to hold the neck

to the arm of the microscope (Cover Image, upper left), and the shorter slot will hold the tube

for the eyepiece and objective in place (Cover Image, upper right).

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Step 4. Next, glue the arm and neck together, making sure that the 1½-inch long slot matches

up with the tall middle piece sticking out of the arm of the microscope (Fig. 7). Also, if need be,

use some rough (e.g., 60-grit) sandpaper to even out the bottom or base of the neck after the

pieces have been glued together, so that the support arm will stand flat on the PVC base of the

microscope. Alternatively, for readers who have access to a wood shop, a belt or disk sander

could be used for this step.

Figure 7. The completed support arm and neck of the microscope.

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Step 5. Now, glue the support arm to the base of the microscope (Fig. 8). To further secure the

arm to the PVC base, use one or two 1¼-inch long No. 6 drywall screws (Fig. 9). Also, we

suggest first drilling guide holes for these screws using a ⅛-inch bit, so that the drywall screws

will pass through the PVC board and trim more smoothly.

Figure 8. The arm of the microscope glued (and secured) to the base.

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Readers can also place felt or cork pads on the bottom of the base (in each of the four corners)

to help level the microscope and provide greater stability (Fig. 9).

Figure 9. Using two No. 6 drywall screws to secure the support arm of the microscope

to the base, and placing felt pads on the bottom of the base (in each of the four corners)

to help level the microscope and provide greater stability.

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Step 6. Next, lay out the pieces for lens tube (Fig. 10) and then put these pieces together. To

do so, first place the objective lens into the ¾-inch Schedule 80 (dark gray) PVC bushing (Fig. 10,

bottom left). As discussed above, the “shoulder” of the objective (i.e., the raised ring just

below the threads) should keep the objective from falling through the bottom hole in the

bushing. Next, insert the PVC tube into the bushing to hold the objective in place. The bottom

of the tube should fit firmly up against the shoulder of the objective (pinning it to the bottom of

the bushing).

Figure 10. The parts for the microscope tube, which holds the eyepiece

and objective (left) as well as an assembled tube (right).

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As explained above, if the PVC tube is too big (and does not slide far enough down into the

bushing), then wrap a piece of sand paper around the end of the tube to sand down the outside

wall until the tube will fit snugly up against the objective. Alternatively, if the PVC tube is too

small (and does not stay fixed in place when slid into the bushing), wrap a few layers of

electrical tape around the bottom of the tube until it holds the objective firmly in place.

Next, to improve the image seen with the microscope, roll a rectangular piece of black

construction paper (roughly 3 inches x 5½ inches) into a tube and insert it into the PVC pipe

(Fig. 10, center). This will help to block out any ambient light from the surrounding room.

Alternatively, readers can use a thicker piece of Schedule 80 (dark gray) PVC pipe – although

these parts tend to cost more than their Schedule 80 (white) PVC counterparts.

Now, place the ¾-inch Schedule 40 (white) PVC coupling onto the top of the tube and twist the

two pieces together to provide a tight fit. Then, wrap several layers of electrical tape around

the base of the eyepiece, so that it fits snugly into the coupling.

Also, please do not glue either the white PVC coupling or the gray PVC bushing to the PVC tube.

Instead, simply use the natural “compression fitting” of these various pieces to hold them

together, so that the parts can be easily slid on and off. That way, it will be easier to switch

eyepieces, objectives, or even tube lengths in the event that this becomes necessary.

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Step 7. After assembling the lens tube, cut out a 1-inch wide strip from one of the plastic

weight boats. This strip will help to secure the tube to the neck (Cover Image) while also

allowing the tube to slide up and down in order to allow for “coarse” adjustments in the focus.

Further note that one large plastic weigh boat will make several 1-inch wide strips.

Figure 11. Cutting out a 1-inch wide strip from a plastic weight boat to later hold the

lens tube in place.

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Step 8. Next, cut out a 3½-inch diameter circle from the other plastic weight boat. Then, trim

this disk as need, so that it will fit into the top of the male PVC coupling. This plastic disk will

serve as a diffuser for the PVC microscope, which will help to soften the intensity of the LED

light striking the sample. Also, depending upon the brightness or intensity of the LED light

used, this diffuser may or may not be necessary.

Figure 12. Cutting out a 3½-inch diameter circle from a plastic weight boat to use as a

diffuser in the adjustable stage of the microscope.

In addition, one simple way to make this plastic circle is to turn the male PVC coupling upside

down and place it on top of the plastic weigh boat. Then, use a permanent marker to trace

around the outside of the coupling. Finally, cut out the plastic circle and trim it to size.

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Step 9. To make the adjustable stage for this microscope, we follow the same steps described

in the Supporting Information (S4) for our OPN Scope article. Specifically, we cut ¾ of an inch

off the top of the male PVC coupling (Fig. 13, top right), using a chop saw.

Figure 13. Converting a standard set of 3-inch male and female PVC couplings (left) into

the adjustable stage for the PVC microscope (right).

Next, we place the female PVC coupling into in a vice that has been secured to the platform of a

drill press. We then drill a small (e.g., ⅛-inch) guide hole into the bottom half of the coupling

(roughly ¾ inches below the “collar” around the top). Then, using that guide hole, we drill a 1½-

inch diameter hole into the bottom half of the female PVC coupling (Fig. 13, bottom right), so

that students can easily turn on and off the push-button LED light that will be placed in there.

Also, we suggest using a “paddle” bit to drill this large hole into the PVC coupling since this type

bit is specifically design for this type of task, and the long pointed end of the paddle bit should

fit nicely into the guide hole. However, please be careful when using the paddle bit to drill into

the PVC coupling since the long pointed end of the bit can easily pierce the other side of the

coupling once the hole has been finished.

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Step 10. To assemble the adjustable stage, first lay out the parts (Fig. 14A) and then start

putting the stage together. Specifically, place the 3-inch female PVC coupling over the push-

button LED light and drop the plastic disk into the top of the 3-inch male PVC fitting (Fig. 14B).

Next, place the round PVC disk on top of the plastic disk (Fig. 14C) and, finally, twist the two

couplings together (Fig. 14D). Also, it is this very feature that enables the stage to provide a

“fine” focus for the microscope once the parts have been assembled.

Figure 14. Assembling the adjustable stage for this PVC microscope from its component

parts.

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Step 11. To finish assembling the microscope, wrap the 1-inch wide strip from the plastic weigh

boat around the PVC tube to hold it to the neck, as shown in Figure 15 below. Then, wrap

labeling (or other) tape around the top, bottom, and sides of the neck to hold the strip from the

weigh boat in place (Fig. 15). Next, wrap the rubber bands around the plastic strip and the back

of the support arm to hold the PVC tube into place (Fig. 15). Finally, place the adjustable stage

(with the push-button LED light) onto the base of the microscope. Now, the bright-field version

of the OPN Scope is ready to use.

Figure 15. A completed bright-field version of the OPN Scope.

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Using the Microscope

Although using the bright-field version of the OPN Scope is fairly intuitive, we provide some

basic guidance here on how to set up and focus the microscope.

Step 1. Place a slide on the adjustable stage and center it under the objective lens (Fig. 16), and

then turn on the push-button LED light by reaching into the large hole drilled into the female

PVC coupling.

Figure 16. Placing a prepared slide on the adjustable stage made from

PVC couplings.

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Step 2. To bring a sample into focus, first look through the eyepiece and slowly slide the PVC

tube up or down until the image becomes visible (Fig. 17). This is a coarse adjustment, which

may require fine adjustment later.

Figure 17. Moving the PVC tube up or down as a “coarse” adjustment to

bring an image into focus initially.

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Step 3. For fine focusing, hold the bottom of the adjustable PVC stage with one hand while

slowly turning the top with the other hand (Fig. 18). The image should become clear and sharp.

Also, while this approach does rotate the image in the field of view, we have not found this to

be an issue at lower magnifications (e.g., 40x or less).

Figure 18. Twisting the male PVC coupling while holding onto the female

coupling in order to provide a “fine” focus.

However, as explained in the Supporting Information (S4) for our OPN Scope paper, at higher

magnifications (e.g., 400x), this technique can rotate a sample out of the field of view. As a

result, students will likely need to use a steady hand when viewing samples at high

magnification (which might be more appropriate for older students or more advanced classes).

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With respect to the quality of the images, because this PVC microscope uses standard

microscope optics and a fixed tube length, we have found that it can generate images that are

comparable to those of a commercial model (Fig. 19).

Figure 19. Images of a Pinus root taken at 40x magnification using

a Celestron 2-MP digital imager and (A) the bright-field version of

the OPN Scope or (B) an Olympus CH-2 commercial microscope.

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In addition, there are a number of relatively inexpensive digital microscope cameras available

online that can be used in place of a standard eyepiece and which will enable students to take

photographs of their samples (e.g., AM Scope, Moticam, and OMAX). However, when selecting

a digital camera, please make sure to consider the weight of the device since the rubber bands

that hold the PVC tube in place may not support a heavy camera.

For example, one model that we have successfully used with this version of the OPN Scope is a

2-MegaPixel digital imager made by Celestron, which now provides related software that is

compatible with both Windows and Mac computers (click on the “Support” menu item in the

above link to access these programs). Celestron also makes a 5-MegaPixel digital imager as

well, which readers might find useful.

Converting the PVC Microscope for Overhead Illumination

Besides serving as a bright-field microscope, we have found that this version of the OPN Scope

can also be easily converted to provide overhead illumination for viewing other 3-dimensional

samples. To make this conversion, we simply use a rectangular piece of cardboard

(approximately 5 inches x 3 inches), an inexpensive keychain LED penlight (roughly, $2), and

four Scotch “Extreme” Fasteners ® to hold these parts to the PVC microscope (Fig. 20).

Figure 20. Placing Scotch “Extreme” Fasteners ® on

the cardboard triangle and LED penlight to provide

overhead illumination with the PVC microscope.

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Specifically, we fold the piece of cardboard into the shape of a triangle and then glue it closed

with super glue (Fig. 20). Note that, on one side, there should be a small amount of overlap

between the pieces, so that the super glue can hold the cardboard together (Fig. 20). Next, we

place Scotch “Extreme” Fasteners ® on the neck of the PVC microscope, the two larger sides of

the cardboard triangle, and the flat side of the LED penlight (Fig. 20).

We then fasten one side of the cardboard triangle to the neck of the PVC microscope and the

LED penlight to the other side of the cardboard triangle (Fig. 21). Students can then turn on the

penlight, place their samples in a Petri dish or on the flat PVC disk, and look at them under the

PVC microscope (Fig. 22).

Figure 21. Providing overhead illumination with the PVC

microscope.

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Of course, if using a standard 10x eyepiece, this version of the OPN Scope will still provide a

total of 40x magnification (since 10 x 4 = 40), as shown in the images of common items

contained in Figure 22 below. Nevertheless, as previously explained, readers can also purchase

5x eyepieces on the AM Scope website, which would cut the total magnification in half (i.e., to

20x since 5 x 4 = 20). Alternatively, readers could obtain eyepieces or objectives with even

lower magnifications, which would further reduce the total magnifying power of the scope.

Figure 22. Overhead images of (A) 60-grit sandpaper, (B), the edge of a rusty razor

blade, (C) the “W” in “We the People” from a U.S. Quarter, and (D) threads from a gauze

pad (all taken at 40x magnification with a Celestron 2-MP digital imager, using overhead

illumination with the PVC microscope).

Conclusion

Like other OPN instruments that we have developed, we hope that the bright-field version of

the OPN scope will help to promote science education among (and facilitate scientific

exploration by) students at all levels. We further encourage readers to use or modify this

design to fit their particular needs, and we include in Figure 23 below some examples of other

wooden or PVC microscopes that we have made to provide some inspiration on this point.

http://pages.stolaf.edu/opn-lab/equipment/ 29 January 9, 2017

Figure 23. Other wooden and PVC microscopes that we have made.

Hazards

As explained above, working with power tools can pose many significant risks, which are as

dangerous as they are obvious. As a result, readers who are unfamiliar with these types of

tools should work with an experienced craftsperson in order to avoid serious physical injury.

In addition, readers should make sure to wear the proper protective equipment when working

with tools of any kind, including wearing the necessary eye and ear protection.

Disclosures

The authors declare that they have no conflicts of interest related to any product, brand,

company, website, or other item discussed in this manual. Indeed, as with other open source

instruments and equipment that we have developed, http://pages.stolaf.edu/opn-

lab/equipment/, we encourage readers to improve upon the designs set forth in this manual by

using other materials and equipment in addition to the insights and inspirations provided by

their own experiences.

http://pages.stolaf.edu/opn-lab/equipment/ 30 January 9, 2017

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