SEM and TEM: what’s the difference?
Electron microscopes have emerged as a powerful tool for the characterization of a wide range of materials. Their versatility and extremely high spatial resolution render them a very valuable tool…
Scanning Electron Microscopy (SEM)
What is Scanning Electron Microscopy (SEM) A typical SEM instrument, showing the electron column, sample chamber, EDS detector, electronics console, and visual display monitors. The scanning electron microscope (SEM) uses…
Transmission Electron Microscope
A Transmission Electron Microscope (TEM) utilizes energetic electrons to provide morphologic, compositional and crystallographic information on samples. At a maximum potential magnification of 1 nanometer, TEMs are the most powerful microscopes. TEMs…
MICROSCOPE IMMERSION OIL EXPLAINED
WHY USE MICROSCOPE IMMERSION OIL? When light passes from a material of one refractive index to another (for example: from glass to air), it bends. In the space between the…
Resolving Power
The resolving power of an objective lens is measured by its ability to differentiate two lines or points in an object. The greater the resolving power, the smaller the minimum distance between…
Numerical Aperture and Resolution
The numerical aperture of a microscope objective is a measure of its ability to gather light and resolve fine specimen detail at a fixed object distance. Image-forming light waves pass…
Laboratory diagnosis, treatment and prevention of Corynebacterium diphtheriae
Specimen Dacron swabs from the nose, throat, or other suspected lesions must be obtained before antimicrobial drugs are administered.Swabs should be collected from beneath any visible membrane.The swab should then be…
Direct Microscopic Counts
Studies involving the analysis of materials including food, water, milk, and, in some cases, air require quantitative enumeration of microorganisms in the substances.Many methods have been devised to accomplish this,…
Phase-contrast Microscopy
Phase-contrast Microscopy Unstained living cells absorb practically no light. Poor light absorption results in extremely small differences in the intensity distribution in the image.This makes the cells barely, or not…
Simple Microscope- Principle, Instrumentation and Applications
The optical microscope, often referred to as the light microscope, is a type of microscope that uses visible light and a system of lenses to magnify images of small subjects.There are two basic types of optical microscopes: Simple…
