Biological Sample Imaging

  Imaging System

1. Transmission Electronic Microscope (TEM) Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through it. An image is formed from the interaction of the electrons transmitted through the specimen; the image is magnified and focused onto an imaging device, such as a fluorescent screen, and then detected by a sensor such as a CCD camera. (Rephrased from Wiki “TEM”)		The Hitachi HT7700 is most suitable for imaging biological tissues.
2. Scanning Electronic Microscope (SEM) A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that can be detected and that contain information about the sample's surface topography and composition. The electron beam is generally scanned in a raster scan pattern, and the beam's position is combined with the detected signal to produce an image. (Wiki “SEM”)		Photo shows a Hitachi SEM S8020.

 
 
  Sample Preparation Equipment

1. Ultramicrotome   In ultramicrotome, sample can be sliced with a diamond blade into thin sections no more than 100 nm, which is necessary for TEM observation. Biological tissue, cells, bacteria and some medical materials can be sliced with ultramicrotome after embedding, freezing or chemical fixation.		Leica EM UC7 Ultramicrotome
2. Cryo-ultramicrotome Some materials are only suitable to be sliced at low (cryo-) temperatures, our Leica EM FC7 cryo-ultramicrotome can operate at from -15℃~-185℃, suitable for polymers, rubber and biological tissues.		Leica EM FC7 Cryo-ultramicrotome
3. Critical Point Drier K850 Supercritical drying is a process to remove liquid from specimen without subject to surface tension, which is usually detrimental to the structure. The liquid is first completely replaced by CO2 in liquid phase, at high pressure. Then, CO2 is brought beyond critical point and then allowed to lower pressure, converting to gas phase. The specimen is dried preserving original morphology. (wiki).		K850 Critical Point Drier