Microscopy Vs. Microscopy : An Example Of Scientific Application

Concept 6.1 Biologists use microscopes and the tools of biochemistry to study cells 1. The study of cells has been limited by their small size, and so they were not seen and described until 1665, when Robert Hooke first looked at dead cells from an oak tree. His contemporary, Anton van Leeuwenhoek, crafted lenses and with the improvements in optical aids, a new world was opened. Magnification and resolving power limit what can be seen. Explain the difference. Magnification is the ratio of an object’s image size to its real size. Resolution is a measure of the clarity of the image; it is the minimum distance two points can be separated and still be distinguished

Preparing specimen for electron microscope hard, light microscope still very useful as a window on living cells.

Looking through a light microscope at a cell undergoing division, you see that the condensed

To make the specimen compatible with both forms of advanced microscopy, they sufficiently prepared samples by coupling the specimen with a fluorescence that was also conductive. This technique was accomplished with the FlouroNanogold label, which contains gold nanoparticles covalently bonded to a fluorescence label. That way, the LM worked as well as the EM for the same set of kinetochores that were being studied. The Hec1 protein was stained in this case because this protein naturally delineates the structures to be studied.

Analyze the anatomical structure of ten different organelles in the cell and their respective functions.

A light microscope was set up with the light on a low setting; one large Daphnia was selected and placed in the centre of a cavity slide by using a pipette.

A cell is subject to hypoxic conditions for 20 minutes, then observed under the microscope. The

A light microscope was set up with the light on a low setting; one large Daphnia was selected and placed in the centre of a cavity slide by using a pipette.

In electron microscopy, on the other hand, a beam of electrons with a negative charge, instead of light is sent through a very thin slice of the specimen.  Because the electron beam has a far smaller wavelength than light used in light microscopy, it achieves far better resolution, “the current resolution of limit of the best electron microscope is approximately 0.05 nm atomic resolution, and 4000X better magnification than that of a conventional light microscope”(BSP, S., 2010).  This means that with an electron microscope you can potentially achieve enough magnification to observe the shape of the protein machinery that carries out the work inside of cells. The major limitation of electron microscopy is that specimen

18) Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! Then you realize that this cell is

A small square of a red onion skin (membrane) was observed under a microscope at high power (X40) magnification. The observation showed a large number of onion cells. The structure of one onion cell had a general rectangular shape with a developed cell wall, which gives the rectangular shape to the cell and a cell membrane just beneath it.

A model cell was made of a visking tube filled with ‘cell contents’. The cell contents represent the cytoplasm of a cell structure membrane. The visking tube represents the plasma membrane of the cell. It acts as a semi-permeable barrier as

when these cryoprotectants are added to the cell slowly an ice-crystal forms in a way in which the cell once in a suitable environment can defrost the crystalline structure and reverse the metabolic shutdown.

Finally, the beam strikes a fluorescent screen. The magnified image of the object can be seen on the screen of a television-like monitor. The images formed by a transmission electron microscope are black and white like an X-ray picture. Computers can be used to translate the image information into a three-dimensional colored image.

We have selected the anionic liposomes for TEM studies. TEM images of anionic liposomes were presented in Figure 6. Analyses by transmission electron microscopy of anionic liposomes clarified the differences between the different formulations. Regarding the formulations of anionic liposomes, an overall increase in size of the liposomes was observed after coating which confirms the results found with the analysis of the particle size. In addition, the analysis in TEM allowed us to confirm the coating of anionic liposomes by pectin and / or WPI. TEM images showed that non-coated liposome formulations were mainly unilamellar liposomes, however, a few multi-lamellar type liposomes were found with spherical shape. Unilamellar liposomes are the consequence of the sonication step during the preparation of liposomes. In addition, the TEM analysis allowed us to confirm the coating anionic liposomes by a pectin layer probably due to hydrogen bonds (Zhou et al., 2014). Pectin layer was shown in the microscopy images as a very smooth black layer. Images showed that pectin helped to maintain the shape and integrity of the liposomes (Fig. 7, c). Unlike pectin, WPI did not form an external layer on the liposomes. Alternately, TEM images showed that WPI gave diffused appearance without maintaining the integrity of