Microscope Experiments

Evaluation of a Prototype Oblique Lighting Condenser

admin — Sun, 01 Jul 2007 19:36:30 +0000

Here is an article about the: Machining a Dark field Microscope, that is it possible for a better condenser design that will reduce the time and effort switching between bright field and dark field.

The experiment uses a modified LOMO Biolam (Multiscope) with more potential in transmitted light than my modified Monolux microscope. The capability includes the phase contrast upgrade for the Multiscope, an aplanatic 1.40 NA condenser, and a ball-bearing rotary stage. Its phase contrast condenser design provided the basis for a prototype to show an answer for quick change between brightfield and darkfield when the darkfield stop must be near the aperture diaphragm of the condenser. The phase contrast condenser allows this rapid switch only for the 10X objective, which needs the phase annulus for the 100X objective to attain darkfield. The open position in the annulus wheel provides brightfield with an aperture diaphragm.

After some experiments and comparisons from other methods of microscopy, the prototype condenser exhibits that there is an easy design solution that provides rapid switching among the various illumination modes. The imaging tests using Abbe condenser against the aplanatic condenser proves that a good polarized light microscope must have an aplanatic condenser. It also avoids the need to adjust condenser height for high NA brightfield or darkfield after Koehler illumination has been properly established for the 10X objective. (more…)

Experiment on Works of Nature and Art

admin — Wed, 23 May 2007 06:46:33 +0000

There is nothing that more conspicuously displays the perfection of the works of Mother Nature than a comparison of them with the finest works of art. The contrast between the one and the other is exceedingly striking, and humbling to the pride of man. His best performances, when examined by the microscope, appear coarse and shapeless; but the more closely and clearly we are enabled to inspect these works, the apparent is a supreme excellence. This, be exemplified by a few illustrations. (more…)

Animal Hairs and Insects Scales

admin — Wed, 23 May 2007 06:45:28 +0000

About the year 1826, Dr. Goring discovered that the structure of certain bodies could be readily seen by some microscopes, but not by others. He called these bodies as test objects. In the course of his experiments, he was led to the conclusion that there were two distinct powers in a microscope, namely, defining and penetrating, and that an object glass might posses the one almost to perfection, and yet be totally devoid of the other, or might be perfect in both. At present, however, it is the opinion of the most celebrated opticians that the terms of definition and defining power are the only expressions requisite to be employed to denote the good or bad qualities of any microscope. The test objects now generally employed for ascertaining the merits of any achromatic combination may be divided into three kinds, namely, hairs of animals, scales from the wings and bodies of insects, and the siliceous coatings of recent and fossil infusoria, those of the latter kind being the most difficult of all to define. The following list contains a few of the test objects to which allusion has been made. (more…)

Microscope Experiment On Yeasts and Molds

admin — Wed, 23 May 2007 06:44:40 +0000

There is a tendency to overlook the fungi when thinking about plants. Unlike plants, fungi are not green in color, and they grow without real stems, roots or leaves. Many lead to a parasitic existence for they lack chlorophyll and they are unable to manufacture their own food. Fungi include the yeasts, molds, mildews, and rusts, and they play an important role in mans life. They serve as multitude of uses from the production of champagne to the formation of penicillin. (more…)

Microscope Experiment on Cells and Tissues

admin — Wed, 23 May 2007 06:42:41 +0000

The cell is the fundamental building blocks of all living things. It is the structural and functional unit of all living organisms. To obtain a detailed image of cells, microscope is necessary. The cell theory was first developed by Matthias Jakob Schleiden and Theodor Schwann in 1839. Important functions of an organism occur within the cells and all cells have hereditary information essential for regulating cell functions and for sending out information to the next generation of cells. (more…)

Fixing, Staining and Mounting a Specimen

admin — Fri, 18 May 2007 07:33:45 +0000

Fixation Process

1. Remove the vitelline membrane from the blastoderm and discard it using the forceps and the camels hair brush. Then with a pipette, remove any excess saline solution from the watch glass. Gently position the blastoderm with a camels hair brush to keep its tissues flat and unwrinkled.

2. Fill the pipette with a fixative called Bouins fluid. Flow a few drops of fixative gently on to the embryo by holding the tip of the pipette at the edge of the blastoderm in the watch glass. Work carefully and slowly to avoid wrinkling the preparation. Do not disturb the embryo for ninety seconds and liberally flood it with Bouins fluid. Use a pair of dissecting needles to straighten the tissue in case wrinkling occurs. Fix one and one-half hours for a 33 to 48 hour embryo, a 72 hour embryo may have to be kept in the fixative for as long as four hours. (more…)

Steps in Preparing Chick Embryo

admin — Fri, 18 May 2007 07:32:57 +0000

Accurate observation of the development of a chick embryo and analyzing the details of its formation necessarily needs a microscope. Microscope is very essential and significant in this kind of study and observation. The suitable specimen for embryonic study is the chick embryo. Several procedures are being observed while preparing chick embryos. These are the following procedures: (more…)

Microscope Experiment on Bacteria

admin — Fri, 18 May 2007 07:32:11 +0000

Much of the discovery of medicine happened in bacteriologists laboratory over the microscope glass slide. A few examples of microscopic experiments are those interminable rows of flasks, broths, and cultures of Pasteur, the fleck of greenish mold that awakened the curiosity of Fleming and the study of Behring on effects of deadly bacillus of diphtheria on guinea pigs, and Walkmans discovery of new weapons for a man to battle against health threats and diseases. (more…)

Experiment on Birds Feathers

admin — Fri, 18 May 2007 07:31:20 +0000

Birds are the only animals with feathers and scales. Their scales in their feet indicate their ancestral link to reptiles. Feathers are modified scales, being non living outgrowth of certain skin cells. Examples of these non living outgrowths are the human hair and fingernails.

There are two kinds of feathers foe birds. The contour feathers that cloth their bodies and provide their flying surfaces, and the other one is the down feathers which characterize young birds and sometimes, underline the contour feathers of the adults. Both types of feathers can make interesting preparations and will make great a great study with the microscope. Best source for feathers are pet shops, a pillow factory, or a chicken farm. (more…)

Embryology Study On Fish Eggs And Frog

admin — Fri, 18 May 2007 07:30:27 +0000

Developmental biology is partly concerned on the study of the formation of life which is known as embryology. Developmental biology focuses on how all forms of life begin and how they have developed fully into functioning organisms while the focus of embryology is much narrower. Embryology deals with the study of formation of life and living things. An embryonic study of fish eggs and frogs is fairly discussed in this article. (more…)