what is the minimum ??X in a microscope to be able to see microbes?

400 x is the minimum

1000 x is the ideal but

cheap microscopes sacrifice resolution for magnification. You need high mag AND a clear image and this is generally expensive.

You can have great fun with a lower mag mic looking at slightly larger specimens like pond samples, plant sections, pollen, insect parts etc

Unless you are determined to see microbes (which, to be honest aren't that interesting under the mic) go for a good quality mic with a wide field eyepiece and a max magnification of 400.

John - retired Biology Teacher

It depends upon what you mean by "microbes!" There are microorganisms such as protozoans that can be seen with a 40X but most protozoans are small enough that 100X or even 400X are the best magnifications. If you want to look at bacteria, then 1000X would be necessary.

Go to a biological supply company web page such as Triarch (http://www.triarchmicroslides.com/), Carolina Biological(www.carolina.com) or Wards Science, Inc (wardsci.com) to see the different microscopes available. If you have enough money to buy a scope with a video camera attached, you can capture pictures of your discoveries as well! High quality lenses will make all the difference in what you can see. With better resolution you can often see more than with a higher power lens with poor resolution.

For routine observation of algae, protozoans, rotifers, roundworms and fungi, you should get a microscope with 4X, 10X and 40X objective lenses. Most scopes come with a 10X eyepiece. A good Abbe condenser with an iris diaphragm is desirable as well. You'll need to buy a box of microscope slides, a box of cover slips, a bottle of slowing agent such as Proto-Sol, disposable Pasteur pipettes (medicine droppers) and maybe a set of vital stains. Vital stains will stain the living protozoans so the contents can be observed without killing the organisms. All these materials will be available from the above suppliers. It is a good idea to have some Bon Ami cleaning powder to clean the glass slides although washing in a dish detergent will work. Remember to thoroughly wash your hands after handling pond water or other materials you are observing!

Sources of specimens can be creeks, ponds, lakes, decomposed leaf matter suspended in water, tooth scrapings, cheek cells from inside your mouth, etc.