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d)
Tow the net for 20–30 minutes.
e)
If any sample is stuck in the net, use the squeeze bottle filled with seawater to flush the sample into the
cod end jar. Unscrew the cod end jar from the net and look at your sample. Pour the sample into the
plastic bottle for transport back to the classroom. If any sample remains in the cod end jar, use the
squeeze bottle.
f)
Thoroughly rinse the plankton net, attached line, and cod end jar with fresh water as soon as possible
after collecting the sample. Reattach the cod end to the plankton net and allow the net to dry
completely before storing. If necessary, gently scrub the net with baking soda, then rinse and dry
thoroughly.
g)
Note: It is extremely important to minimize the time from sample collection to analysis. If the sample
must be stored overnight, be aware that a large portion of the zooplankton will not survive. However,
there will still be plenty of organisms to observe so, if collecting the sample the day before is the only
option, it will still be worthwhile. To increase the lifespan of the zooplankton, dilute the sample by
adding it to a bucket of seawater (you will need to re‐concentrate the sample prior to analysis, which
can be done by pouring the water through the sieve). Alternatively, you can prolong the life of the
zooplankton by storing the sample in the refrigerator overnight. Make sure the cap is loosened to allow
air flow to the sample.
4.
Familiarize yourself with the dissecting microscope.
a)
Parts of the microscope
Eyecup
Diopter
Focusing
Ring
Interpupillary Adjustment
Zoom Knob
Upper Lamp
Focusing Knob
Base with Lamp
Stage Plate
Thumb Screw
Stage Clip
Main Power
Switch
Stage Plate
Lamp Dimmer for
Incident Light
Stereo Head
Camera
Cable
Camera
Housing
Vertical Pole
Lock Screw for
Focusing Carrier
Lock Screw for
Support Collar
Prism Bar (On back)
In = Both eyes, no camera
Out = Left eye and camera
Lamp Power
Switches
Incident Light Switch
(from above)
Transmitted Light
Switch (from below)
OFF
ON
OFF
ON
Eyepiece
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b)
Overview of the dissecting microscope
i.
The microscope eyepieces have 10X magnification. Coupled with 1.0X to 4.0X zoom lenses, the
microscope offers a total magnification of 10X to 40X.
ii.
The microscope has a main power switch as well as a power switch for the incident (upper) and
transmitted (lower) light source. The intensity of the incident lamp can be adjusted with the lamp
dimmer on the right side of the base.
iii.
There is a built‐in camera with a USB cable that connects to the computer included with the kit.
You can also use the Motic Images Plus software to capture, annotate, and store images in .jpg,
.bmp, .sfc, or .tiff graphical format. To share the display with your entire class, connect the
computer to a projector or video monitor.
5.
Set up the microscope and computer
a)
Carefully remove the microscope from the action packer (see guide in microscope box for instructions).
b)
Plug in one end of the power cord into the back of the microscope and the other end into a power
outlet.
c)
Plug one end of the USB cable into the back of the microscope and the other into a USB port on the
computer provided.
Note: If you prefer to use your own computer, install the software prior to
connecting USB cable.
d)
Connect the computer to a projector.
6.
Focus the microscope
a)
Plug in the microscope, turn on the main power switch, and turn on the incident light.
b)
Place a piece of paper with writing on it flat on the stage plate.
c)
Look through the eyepieces and adjust the distance between your eyepieces by rotating the bases of the
eyepieces (shown above as “Interpupillary Adjustment”) so that you see only one circle of light
comfortably. Note: If you can only see through the left eyepiece, carefully slide the prism bar in.
d)
Carefully turn the zoom knob to the highest magnification.
e)
Adjust the focusing knob until your specimen is clear and sharp.
f)
The height of the microscope is set for plankton viewing. If you try to view different items or if you
cannot focus clearly, you may need to adjust the height of the microscope along the vertical post.
i.
Turn main power OFF.
ii.
Loosen the lock screw on the black support collar and lower the collar to the base.
iii.
While holding the head of the microscope, carefully loosen the lock screw on the focusing
carrier and adjust the height of the microscope.
iv.
Tighten the lock screw on the focusing carrier.
v.
Slide the support collar up to the base of the focusing carrier and tighten the lock screw.
g)
Zoom in to the highest magnification and focus until the image is clear and sharp.
h)
Zoom out to the lowest magnification. Adjust the diopter focusing ring on the right eyepiece until the
image in the right eyepiece is clear and sharp.
i)
Repeat steps g and h for the left eyepiece.
j)
Check the focus for the entire zoom range. The microscope should now be parfocal, maintaining focus
for the whole zoom range.
7.
Viewing plankton sample
a)
Use a plastic dropper to put a small amount of sample in a Petri dish.
b)
Place the Petri dish on the stage plate of the microscope and look through the eyepieces.
NEVER place a sample directly on the stage plate.
c)
Turn on the transmitted light.
d)
Zoom out to the lowest magnification and focus on the sample
e)
Now you can move the Petri dish and zoom to specimens of interest. Use the dissecting needles to
move the plankton around for easier viewing.