Scan bacteria with an SEM.
The scanning electron microscope (SEM) allows you a two-dimensional view of the surface and structure of a specimen. The SEM uses a beam of electrons to image the structures and an electric field to accelerate the beam of electrons. A deflector plate is what scans the beam across the image; the smaller the beam, the better the image. In microbiology, scanning electron microscopy is useful in viewing the surface structures of bacteria.
Instructions
1. Vacuum the sample bacteria. To do so, place the bacteria in the specimen exchange chamber and press the vacuum control button. This gets rid of any gas molecules before the specimen is coated with gold; not doing this could result in uneven coating or no coating.
2. Remove the specimen from the specimen exchange chamber.
3. Coat the sample with gold using a sputter coater before inserting the image into the scanning electron microscope. The gold will protect the fragile bacteria specimen and provide conductivity for scanning.
4. Mount the specimen back into the specimen exchange chamber and make sure to screw the specimen-exchange rod into the holder.
5. Turn the accelerating voltage button on. Adjust the probe current knob to acquire the right amps for the sample.
6. Align the electron gun beam using "Tilt" or "Shift." Press "Scan." The electron beam will encounter the specimen in the chamber and images can be taken. Click on your imaging controls to access the images.
Tags: exchange chamber, scanning electron, specimen exchange, specimen exchange chamber, bacteria specimen