First Scanning Electron Microscope Case Study

The first scanning electron microscope (SEM) was invented by Manfred von Ardenne in 1937 (McMullan). However, further development of the SEM was accomplished by Charles Oatley and his colleagues at Cambridge University (McMullan; Egerton 17). He and his colleagues acquired their first images from the SEM in 1951 (Egerton 17). The SEM was developed because if a TEM is utilized, a specimen must be made extremely thin to prevent the electrons from dispersing inside the specimen and so the electrons are not absorbed. This was the foremost limitation of the TEM that truly motivated the development of the SEM (McMullan; Egerton 16, 17). The SEM displays the ultrastructure of the specimen, the images have a large depth of focus and shows the surface …show more content…
The SEM was used in this study to analyze how externally adding putrescine would affect the “functional morphology of malformed and healthy floral buds as well as flowers of mangoes.” In the study, a total of 10 16-year-old plants of mango cv. Amrapali were used in this study. This study also consisted of two field trials, one in March 2011 and the other in March 2012. The experiment contained a control group of healthy and malformed panicles of plants with both flowers and floral buds. In the experimental group, putrescine was applied to flowers and floral buds “of healthy and malformed panicles” of the plants. Then three samples from both the experimental and the control group were examined individually under a SEM. The healthy floral buds that were treated with putrescine opened earlier, and developed extremely well compared to the healthy floral buds in the control group. The malformed floral buds that were treated with putrescine normally matured, meaning that they flowered in a healthy manner in which the sepals and petals were normally separated. Whereas the malformed floral buds that were untreated did not flower and displayed fused sepals and petals. The putrescine treated well-developed flowers displayed stamen and carpel that matured well. They also had normal size ovary. In comparison, the untreated flowers showed short stamen and large ovary. The putrescine treated malformed flowers grew like normal flowers with “functional normal-sized ovary.” However, the malformed flowers that were untreated displayed short stamen and large ovary. The overall conclusions made by the authors of the manuscript are that the application of putrescine either