Re: How strong does a microscope have to be to see a microbe?

Interesting question!

Let's answer your question first, and then talk about options for using the scope you have.

For the sake of discussion, let's assume bacteria are 1 micron in diameter... a reasonable approximation. A micron is one millionth of a meter.

Let's also assume that we can see something clearly if it's one millimeter long.

This means that if something is 0.000001 meters long, and we need to make it 0.001 meters long to see it:

0.000001 * 1,000 = 0.001

So you need a scope capable of magnifying something 1,000 times, which is probably beyond the capabilities of your scope.

So, since you can't (easily) make your scope better, you need something bigger to look at. One very common choice, used in many biology classes is "pond scum". Find yourself a pond (maybe this Spring) and scoop up some green muck from the edge, put a bit under the scope and explore. You should find plenty to see!

Moderator's note:
To view bacteria we generally use a microscope with a 100X lens, plus eyepieces on the microscope that magnify an additional 10X = 1000X magnification. The 100X lens is not common on most school microscopes, but will be present on models commonly used in hospitals.