This page contains a number of Scanning Electron Images taken by Jim Ekstrom and his biology students. The images were produced with an ISI 30X SE instrument that has been in operation since April of 1997.
The SEM has been digitized and the image output is captured on a computer.
Permission is required from Jim Ekstrom to commercially these files.
You will need a copy of NIH Image software for the Macintosh files and ImagePC software for the Windows files. Both software applications can be obtained at the Center for Image Processing for Educators : CIPE
To see a sample of the download, click on PREVIEW at the end of the description.
This preview can be downloaded by holding down the mouse button on the image and making your selection.
Bacteria (470K)MACBacteria(488K)WIN In
a bioassay experiment in introductory biology we used Bacillus subtilis and
Bacillus cereus. Samples of these two cultures were plated on a cover slide,
sputter-coated and examined with the SEM. These images can be compared with
light microscope views in the laboratory. PREVIEW
Cosmos Pollen (656K)MACCosmos Pollen(713K)WINA
couple of student teams did projects of Pollen and Allergic Reactions. Air collecting
of pollen did not work very well -- partly because Spring (what little there
is of it in New England) was very late. Instead we sampled some pollen from
what Spring flowers were available and I subsequently did a good deal of sampling
latter on in June. Pollen comes in a great variety of shapes and forms and is
quite beautiful to look at with the SEM. (There are 5 SEM images in this file.).PREVIEW
Lycopodium (648K)MACLycopodium(661K)WIN
Lycopodium spores. These spores come from the plants commonly called
the club mosses. One of the earliest groups of vascular land plants. (There are
4 SEM images in this file.).PREVIEW
Porcupine Quills (302K)MACPorcupine Quills(317K)WIN The
pointed end of the quill is in the upper left corner of these images. I think
it is pretty obvious why removing the quills is difficult ..PREVIEW
Aluminum Foil (378K)MACAluminum Foil (404K)WIN
A typical chemistry exercise is to calculate the thickness of aluminum foil.
The three SEM images included in this download can serve as a reference standard
for this exercise. (At least for this particular piece of foil.) PREVIEW
Mosquito (1.1MB)MACMosquito (1.3MB)WIN
A combination of light microscope and SEM views of certain female mosquitoes
that have tried to obtain some of my bodily fluids over the last two years.
PREVIEW
Springtails (406K)MACSpringtails (575K)WIN
Springtails or snow fleas are speck sized invertebrates that are particularly
prevalent as numerous dust spots on the surface of the snow. The "spring" of
the springtails is readily apparent in these SEM views. PREVIEW
Water Strider (834K)MACWater Strider (527K)WIN
These SEM views of a water strider are particularly good for showing how these
insects are able to make use of the water's surface tension to move around .
PREVIEW
Equisetum or horsetail is one of our most primitive vascular
plants.
Equisetum Stomates
(370K)MACEquisetum Stomates
(410K)WIN Two SEM magnifications showing stomates in the plant
Equisetum.. PREVIEW
Equisetum Vascular
(366K)MACEquisetum Vascular
(386K)WIN Two SEM magnifications showing vascular
structure in the plant Equisetum.. PREVIEW
3-D Images, etc. All of the following images were produced after taking the samples and fixing them in a variety of ways and then coating them in a sputter-coater with a thin layer of gold. Images were observed and digitally photographed under a Scanning Electron Microscope (Red/Blue glasses are necessary to observe the images.)You will need 3-D glasses and if you are using NIH Image or Scion Image go to Photo Mode in the Menu Bar after loading the file.
Equisetum (842K)MACEquisetum(970K)WIN This download contains 3-D views of some of the images
from the two previous SEM views of the equisetum. PREVIEW
Cosmos (150K)MACCosmos (169K)WIN
Two 3-D views of the anther of a Cosmos flower. One view under 33X and the other
showing a single pollen grain under 3,790X. PREVIEW
Spider (184K)MACSpider (210K)WIN
Two views of a jumping spider that became the first invertebrate to be scanned
with our SEM. Found as a dried specimen on the windowsill of my garage. PREVIEW
Egg Shell (95K JPEG) Having pores in an egg shell
is vital. As the embryo develops there has to be an exchange of oxygen and carbon
dioxide through this calcium carbonate shell.PREVIEW
Velcro (56K JPEG)
Velcro is the invention of George de Mestral, a Swiss mountaineer. It is the
matching up of the nylon loops and hooks that makes it "holdfast"..PREVIEW
Lettuce Wrap(83K JPEG)
Having pores in an egg shell is vital. As the embryo develops there has to be
an exchange of oxygen and carbon dioxide through this calcium carbonate shell.PREVIEW
A collection of everyday images
The PREVIEW1 function will generally show a single image of what is being discussed while the PREVIEW2 will have a composite of several images. Once you have the PREVIEW you can click on it to Save it, Print it, or what have you..
Paper
There seems to be almost unlimited possibilites when it comes to paper. The paper that we use in copying work has a rough tangle of fibers PREVIEW1 - PREVIEW2 compared to a more orderly weave that you would find in something like "Kleenex" PREVIEW1 - PREVIEW2. In the science laboratory we use a coarser form of the this popular tissue for cleaning equipment and generally "mopping-up" various stains. This material has a trade name of KimWipe PREVIEW1 - PREVIEW2.
Filter paper is composed of several different "grades". The first example is termed #1 PREVIEW - PREVIEW2) while the second grade that we have is #5 PREVIEW1 - PREVIEW2. Compare the relative compactness of the fibers. Which type would you use for "fine" filtering something?
Should you make a mistake in on your sheet of paper, well you can always use white-out correcting fluid.PREVIEW1 - PREVIEW2 Finally, we can take a look at the sticky side of all those Post-It notes.PREVIEW1 - Post-It Download (500 K) (The download portion contains a comparison with the "non-sticky" portion.
Needles:
Included, along with the biblical camel going through a needle are various images of needles, needle and thread PREVIEW1 - PREVIEW2 and a calibrated camel image going through a needle. (The average came/ by the way is 7 feet tall at the hump. How much would you have to reduce the camel in size to get it through the needle?)Camel (56 K)MAC
Potato Chips :
When potato chips are fried, as part of their production process, the hot oil causes internal water in the chip to vaporize, forming air pockets internally. (Some of these pockets may contain oil) This makes for a certain "crunchiness" on eating. PREVIEW1 shows a very "crunch" chip while PREVIEW2 shows a more mundane chip. However, overly crunchy chips can burst inside the bag and produce a great amount of less desirable fragments
If you would like further information, or to get in touch with Jim Ekstrom, feel free to e-mail
jimekstrom@comcast.net
Science Department
Phillips Exeter Academy
20 Main Street.
Exeter, NH 03833
U.S.A.
(603)
777-3269
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