Buying a Microscope

A microscope opens up the invisible world of mold at your home. I don't know how mold inspectors function without one.

That said, what you and I do with a microscope on-site would not hold up in court. We do not have advanced certificates in microscopy, such as from McCrone Research Institute in Chicago (over $10M and geared toward lab technicians), nor are we sending all samples to a microbiological lab – not that selected samples couldn’t be sent for independent third-party confirmation. I make it a point to include photo documentation of mold seen under my microscope with reports, but even that documentation may not mean much in a court case.

My interests have always been in serving clients who have health issues. One client put it this way when I informed her that I did not hold the license to inspect in her state: “I’m not interested in a license. I want you and your microscope.” So, what I do is for the client’s information only. If a client has a legal issue going on in that state, I refer her to a state-licensed inspector.

Happily for you and for me, working with a microscope and identifying mold under a microscope is not rocket science. If you can recognize regular shapes such as spheres, grapes, bananas, clubs, and hand grenades, you can recognize mold….but I’m jumping ahead to the tab, Working with a Microscope. First you need to actually procure a microscope….

You might start here: How to Use the Microscope, which has an overview of a microscope (from The Biology Corner website).

Buy from a dealer or on-line?

A microscope should be serviced periodically or may need an initial adjustment, so establishing a relationship with a microscope dealer is recommended. Larger cities would likely have dealers, because schools and universities require servicing of their microscopes.

You get what you pay for, but some lower end microscopes are better than others. I use an Accu-Scope, and that has worked fine for years. Several colleagues have bought cheaper microscopes with plastic parts, even with photography capability, online, but have been disappointed with the optics. Optics may be able to be improved by upgrading the lenses, again, preferably from a reputable dealer.

Purchase options

Accu-Scope

ACCU-SCOPE PROs

At least two dealers have recommended this brand as of better quality for a more affordable microscope, with metal gears, etc. – range of $600-800. My Accu-Scope has a lot of miles on it, and I recently added a second one, EXC-120 series.

I had 15X ocular Plan (better quality) lenses put in instead of the customary 10X that the microscope came with.

I purchased the Plan lenses for the objective lenses as well.
To summarize: I’d recommend Plan or other quality lenses for:
15X ocular lenses (2)
4X, 10X, and 40X objective lens.

I didn’t purchase a 100X lens because I haven’t needed to magnify to 1500 X (mold is not that small) or work with oil immersion.

"Oil immersion" means that you need to add a drop of immersion oil onto the microscope slide (over the tape). Then, the 100X lens sits in the immersion oil, because the oil becomes part of the focusing at the higher magnification. This setting is not really needed. Oil that goes on the lens also has to be cleaned off the lens.

For almost all my work, using 600X magnification (what many labs use) suffices. Figure the magnification by multiplying the number on the ocular lens with the number on the objective lens. Multiple 5X ocular lens times 40X objective lens, for 600X.

With the 4X and 10X ocular lenses, that gives me 60X and 150X magnification. These can be useful for a quick scan of the tape but I don’t study the mold at these lower magnifications.

A plus for this microscope is that you can get one that is rechargeable. However, I like the new stage better with the EXC-120 Series microscope and would recommend that.

My colleague, Sal La Duca (www.emfrelief.com), set me up with a simple webcam (under $20) and image-capturing software, and the AMCap image capture software might have been around $35. (See below for the steps for photographing an image.) The Accu-Scope offerings include a trinocular microscope with a photography attachment (close to $2,000 for both).

That said, you might also check out this link: www.mccrone.com/mm/a-webcam-looking-through-the-microscope. I’d need help in getting this set up, but either the Accu-Scope or the McCrone set-up sounds like an improvement over my $4 webcam and worth planning for.

Also see www.mccrone.com for course listings for microscopy. They are a professional group that trains many lab technicians. Basic courses may be helpful to you, but to my knowledge (and from what I see on their course listings), nothing is directly applicable to house inspections.

One colleague spent a pretty penny to take a similar course for lab technicians somewhere in New England and said he learned a lot of detailed information that he didn’t need to know and not enough for what his inspection needs were.

So where will you learn the information you need to inspect? You will get the basics at this website…and on-line, at a certification course, and perhaps in a reference book. Here is the one that I still refer to, though I believe there are more recent reference books:

Identifying Filamentous Fungi – A Clinical Laboratory Handbook, by Guy St-Germain and Richard Summerbell, 1996. They also have a more recent book, Identifying Fungi, 2010, which I haven’t seen.

When I started this business, 25 years ago, I took a Basic Microscopy refresher course at a local college, having already worked with the microscope in a college class in parasitology. I was already doing home inspections at the time, and when I showed the local professor the reference book I was using, he replied, “Oh, excellent! I’ve been looking for something like that.” We haven’t progressed much beyond that.

Essentially, using that reference book through many hours of discovery, I taught myself how to find and identify common fungi at houses. What I learned has matched up fine with lab results, as there has been opportunity for comparison.

ACCU-SCOPE CONS FOR MY PHOTOGRAPHY SET-UP

The focus at the Accu-Scope is not quite the same as the focus on the computer monitor. This is a bit of disadvantage when sitting with clients who want to see on the monitor what I see under the microscope. The focus isn’t that far off, and I can easily focus for the monitor, but it would be nice to have a one-on-one correlation.

With a binocular microscope, you can look through it with both eyes – but not when the webcam is attached, because that needs to be taped onto one eyepiece. A trinocular microscope eliminates this disadvantage.

A used microscope

The dealer I’ve been using said that American Optical is a solid brand for buying a used microscope. That sounded like a clue, so I bought two used student binocular compound American Optical microscopes, #10. Both had fairly stiff movements, which might have come from sitting on a shelf for years but which were still somewhat stiff after the dealer’s adjustment, and with one, the focus between the eye piece tubes was off. Both were returned. I decided to stick with new microscopes.

My first microscope, years ago, was used. When I finally got around to using a gaussmeter (for AC magnetic fields, like the powerline issue) in the vicinity, I was amazed at the level of AC magnetic field exposure I was getting from that microscope. So, if purchasing a used microscope, I’d check it with a gaussmeter. Levels should be under 1 mG, and I was being exposed to about 30 mG, right near my head, for all the many hours I was using that microscope. Not good. The American Optical ones were ok.

Microscopes either use regular light bulbs or LED lighting. Regular lighting might be a bit better for photography, but I use the LED for less exposure to AC magnetic fields.

Miscellaneous comments re: buying a microscope

Microscopes for lefties: Most microscopes are for right-handed folk, but microscopes can be adjusted for left handed folk. The dealer is able to do this.

Two eyepieces (binocular) rather than monocular: Spend a little more and get a binocular microscope for viewing with two eyes, not a microscope for just one eye. If planning on photography, get a trinocular.

Quality microscopes have a movable stage. With others, you have to manually move the slide back and forth over the stage. Don’t even think about buying one where you have to manually move the slide. Get one that has the knobs to move the stage back and forth.

Sometimes bulbs blow out – but not usually LED bulbs. Ask the dealer if you should buy an extra bulb and how to replace a bulb. Tip: If replacing a bulb, hold the bulb in a tissue. Don’t get oil from your fingers on the new bulb, because that could shorten the life of the bulb.

The microscope also may have a fuse. Ask the dealer about that, too. In 25 years of microscope use, I’ve never had a blown fuse, but if it did, I was told that I could get another at a local electrical supply house.

Focusing issues

A sign of a properly adjusted microscope is that the focus should be about the same at all levels of magnification. In other words, if you focus the ‘scope at the lowest magnification and then want to move to the higher magnifications, you would have to do only a little turning of the fine focus knob to restore focus. This is one test you can do at the microscope shop before you carry your microscope home.

Tip: If you are having trouble focusing, switch to the lowest level of magnification and focus there. Then return to the higher magnification. If you still are having trouble focusing, make sure your slide is not upside-down, i.e., with the tape on the underside of the glass.

Close your left eye and focus the microscope to your right eye. Then open your left eye and turn the left eyepiece until the lenses are in focus for both eyes.

Microscope photography

Here’s what I have used for years: a cylinder-shaped webcam (around $10-$30 on Amazon, with the clip removed) that I tape onto one eyepiece (and then use just one eye to look through the other eyepiece of the microscope). Along with that webcam, I use AMCap video and still capture software, about $30. Another program (free) that you’ll need is a cropping program, such as the free IrfanView for Windows. (I understand there is also a Snip-It program with Windows that would do the same, but I haven’t worked with that.)

Here’s the procedure to display on your monitor what you are seeing under the microscope and then to take a picture of it for your records:

Plug the webcam into a USB port of your computer.

Tape the webcam onto one of the eyepieces of your computer. I tried this using an instructor microscope, with a 3rd eyepiece on the microscope, but did not succeed in getting a satisfactory focus. The McCrone instructions sound more hopeful of success with a trinocular.

Start the AMCap software.

Turn on the microscope and focus your slide on the computer. You can either study a slide from the microscope or from the computer, but I find it easier to work from the microscope.

When you find a view that you want to take a picture of, focus it and then hit Print Screen (PrtSc) on the computer keyboard.

Open IrfanView and paste (Edit -> Paste) what you just copied to the clipboard into IrfanView (Do not close AMCap, or you’ll lose your picture.)

Select the part of the picture you want to save by pulling a box around it.

Under Edit, choose "Crop selection"

If you, optionally, want to draw a circle or a rectangle around part of the picture, under Edit choose Show paint dialog. This opens a new vertical window.

Go to the new window and make your selection. For highlighting, you can draw a circle or square on the image. You can also add arrows to point to particular points of interest. There are multiple choices for enhancing your photo, so feel free to explore. Another is to write text on the photo.

After you have the final product, under Edit, select Copy.

Finally, Paste the photo into a file document to save it. Or, you can click File -> "Save as..." to save the image as a picture in any of many formats (JPG is perhaps the most popular format). IrfanView can be closed at this point.

A "kids" microscope

For a few years in my twenties, each year I’d buy myself a present, and one year it was a stereo microscope. I made this purchase after taking a course in marine biology where I viewed the awesome tiny creatures that lived in sand at the shoreline of a bay. We put the sand through a metal sieve and gathered up the little creatures, which were placed in a Petri dish containing bay water. The dish was set on the microscope stage, and we could observe the tiny critters moving around.

For awhile, I had been bringing that old microscope on some inspections, naming it the “kids’ microscope.” With a stereomicroscope, kids can look at solid objects, such as cats’ hairs, flowers and leaves, sugar crystals, bugs. This microscope goes up to 30x magnification and is pretty indestructible. At one home, I pulled up to the driveway, and there were four youngsters standing in a row, waiting, “Are you the science teacher? Can we see the microscope?”

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