Examining Your Blood Under A Compound Microscope
Experimenting on one’s own blood is probably one of the most exciting science activities that we can do with a kids compound microscope. There are many things that students and children learn from looking at the makings of their blood under high power magnification.
Before starting with this microscope activity, teachers should remind their students to put extra care in performing the microscope activity. Before drawing one’s blood, make sure that you have rubbed your finger in alcohol and the needle to be used is thoroughly sterilized by heating it in a flame. You can also obtain the finger pricking equipment at a local drugstore, as people with diabetes use these devices daily to check their blood sugar levels.
A single drop of blood is enough for the science experiment. Place it on a thoroughly cleaned and new blank microscope slide and quickly put on the cover slip over the blood drop. Surround the edges of the cover slip to prevent evaporation. Then place the slide on the microscope stage to start the observation.
Our blood under a high power kids microscope looks like flattened circular discs that float about. These are our red blood corpuscles. Each of them has a center that is darker than the rim as a result of the light refracting from the disc’s double concave form. They also tend to approach each other, pile up or adhere to each other’s edges.
Humans, as well as those of the higher mammals, have circular red blood corpuscles. There is an exception to the camels which have oval red corpuscles. This is also the same with reptiles, birds and fishes.
If you look closely at the blood under a child’s compound microscope, you will also notice a few smaller discs. These are the white blood corpuscles that, as we have observed, are far outnumbered by the red blood corpuscles. Watching the white blood corpuscles under high power compound child microscope, you will observe that they change their form while moving from place to place. They engulf the particles that they chance upon their course and eject them afterwards.
Another educational microscope activity that can be done with blood using a kids compound light microscope is to observe it as a stain. Instead of looking at it fresh and undisturbed from our bodies, we will observe it as a stain on clothes or other materials.
To proceed to this microscope activity, a piece of cloth is necessary with a stain of blood on it using the precautions as mentioned above. You have to let the blood thoroughly dry and afterwards scrape a little of it on a microscope slide. Add a few drops of salt solution on the dried stain on the slide. Heat it over a flame until the solution is completely evaporated. Kids or children should be reminded that they must not do this alone and must have their parents or teachers guide them.
When heated over a flame, it will leave a reddish-brown residue. Put a cover glass and flood it with acetic acid. When there is too much acetic acid that remains under the cover, heat it again until the acetic acid boils and evaporates. When the slide cools, position it on the microscope stage and start examining the blood sample.
Under high power magnification, with a kids compound light microscope, blood stains look like crystals in small and narrow rhombic plates that are dark-brown in color. These are called the hemin crystals and come in various sizes that lie across one another. Laboratory experiments done on suspected blood stains will prove that it is blood when they see the crystals. This is one way to tell if a substance is really blood or just something that resembles blood.
Experimenting on one’s blood under a high power compound light microscope may give the students, kids or children a touch of what it feels like to be in a forensic laboratory where they study evidence on crimes.
In any case, looking at blood under a high power compound microscope is a rewarding and challenging experiment for kids, students, and teachers alike.
