Posts of the Category: Labwork
This category contains posts with labwork that can be done in a school.
Observing bacteria under the light microscope
It is possible to use non-toxic stains (such as ink for fountain pens) to stain yogurt bacteria in-vivo.
Making a wet mount for microscopy
A wet mount (or temporary mount) is one of the most common ways of observing specimens under the microscope. The sample to be viewed floats in a layer of water which is between the slide and the cover glass. The water performs an important optical function. Without it, the resolution is lower. The general procedure […]
Making mounts of pollen grains
Permanent slides of pollen grains can be used as a reference for identifying unknown pollen samples. It is therefore important, that the pollen grains remain in an authentic, natural shape. The preparation and mounting of the pollen can introduce artifacts: the pollen may lose some of its pigment, start to shrink and shrivel or absorb […]
An overview of mounting media for microscopy
Mounting media are needed for making permanent slides. The mounting medium holds the specimens in place between the cover slip and the slide. The choice of the right mounting medium is a separate topic all on its own. There are countless commercial and home-made mounting media available. Which ones should one use? In many cases […]
Choosing the right mounting medium for making permanent slides
There are numerous different mounting media available for making permanent slides. What factors determine the choice of the mounting medium? Here are some possible points to consider. Toxicity: Solvent-based mounting media (such as Eukitt and Canada Balsam) require the specimen to be in xylene prior to embedding. This substance is toxic. Other mounting media, such […]
Here is yet another link to an article from Popular Science magazine. It deals with the isolation, fixing and staining of bacteria. I would not recommend the use of some of the solvents that they use (such as xylol) with children, however. They also describe a blood smear preparation, what I do not recommend for […]
Stains and reagents for microscopy
I found an article in Popular Science Magazine (see link below) which gives a general overview of different stains that can be used in microscopy. The article divides the stains into three categories: Common household chemicals: this includes Iodine, for example. They are very readily available. Substances used mostly for microscopy: Methylene blue, Hematoxyline, and […]
Introductory Microscopy Projects for Schools
Are you looking for simple microscopy projects for classrooms? Here is a list of ideas. Do not forget about safety measures!
Making a Soil Culture for Growing Algae
It may be necessary to grow large amounts of green algae (and other microorganisms) to be used for microscopic observations in schools. A soil culture allows you to enrich various types of algae.
Observing Potato Starch Grains
Potato starch grains are an ideal for observation in polarized light and in dark-field. Sample preparation is simple and straight-forward.
Dry-mounted permanent slides
Wings of insects, small insects and other small specimens do not have to be enclosed in a mounting-medium, they can also be dry-mounted. If they are completely dry, then they will also store for a long time.
Processing Specimens for Microscopy
Not all microscopic specimens can be observed directly with a compound microscope, many of them need to be brought into a form which is suitable for observation. Different specimens have to be processed differently. This article gives an overview of different preparation methods.
Observing a Kiwifruit
Soft specimens can be observed by squashing a small sample between the slide and the cover glass. Here I would like to present: a Kiwi fruit
Fructose Mounting Medium for Permanent Slides
Many mounting media for making permanent microscope slides include organic solvents and are less suitable for the use in classrooms, at home and with children. In this article I would like to show you how to make fructose syrup to be used as a safe mounting medium.
Observing Brownian Motion
Brownian motion is the random movement of particles. It is possible to observe this movement under the microscope.