Posts of the Category: Labwork
This category contains posts with labwork that can be done in a school.
Euparal Mounting Medium
Euparal is a semi-synthetic mounting medium used in microscopy. It is slightly yellowish in color, flows well and cures after a few days. After curing, it becomes very hard but not brittle, keeping elasticity. Euparal also adheres strongly to glass. It has a refractive index of 1.5174. Compared to other mounting media, Euparal has a [...]
Fixing specimens for making permanent slides
Before specimens can be processed for making permanent slides, they may need to be fixed. This step kills the specimen and preserves the structures. It also prepares the specimen for staining. There is no one single method to fix a specimen, too much depends on the nature of the specimen itself and on the subsequent [...]
The hemocytometer (counting chamber)
The hemocytometer (or haemocytometer or counting chamber) is a specimen slide which is used to determine the concentration of cells in a liquid sample. It is frequently used to determine the concentration of blood cells (hence the name “hemo-”) but also the concentration of sperm cells in a sample.
The effect of the mounting medium on specimen and image quality
The mounting medium can have a significant effect both on the image quality and on the specimen itself. I tried a little experiment by observing pollen from a plant (in this case the buttercup, Ranunculus), mounted in five different ways: Air-mounted, with no cover glass Air-mounted, with a cover glass Mounted in water (temporary mount) [...]
Stereo microscope projects
Let’s have a look at some stereo microscope projects that you can do with children.
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 [...]