Microscopic Methods in Microbiology

Flashcards covering fluorescence microscopy, immunofluorescence techniques, and the fundamental principles, history, and physics of electron microscopy based on the lecture notes.

Fluorescence

A principle where substances absorb short wavelength light rays (UV) and release light with longer wavelengths, visible through a special filter.

Fluorochromes

Fluorescent dyes used to stain microorganisms that do not naturally fluoresce, making them appear as luminescent objects against a dark background.

Auramine O

A fluorochrome that glows yellow under UV light and is specifically used to identify $Mycobacterium tuberculosis$.

Fluorescein isothiocyanate

A fluorochrome used to stain $Bacillus anthracis$, the causative agent of anthrax, making it appear as a light green rod.

Immunofluorescence

A diagnostic technique also known as the fluorescent antibody technique, where fluorescently labeled antibodies bind to specific antigens like bacteria.

Electron Microscope

A microscope that uses accelerated electrons as a light source to achieve a resolution of approximately $0.4\,nm$ for biological preparations.

Knoll and Ruska

The scientists who constructed the first electron microscope in 1931.

Vacuum in Electron Microscopy

An airtight space required within the tube to prevent electrons from losing kinetic energy through collisions with air particles.

Electron Gun

A component at the top of the electron microscope consisting of a tungsten filament (cathode) heated to $2000\,^{\circ}C$ and a hollow anode.

Electromagnetic Lenses

Components used in an electron microscope to focus the electron beam, replacing the glass lenses used in light microscopy.

Planck's Constant ($h$)

A physical constant used to calculate the wavelength of a particle, valued at $6.62 \times 10^{-34}\,J\,s$.

Mass of an Electron at Rest ($m_0$)

A constant value of $9.1 \times 10^{-31}\,kg$ used in the calculation of electron wavelengths.

Wavelength Formula ($\lambda$)

The expression used to calculate the wavelength of a moving particle like an electron: $\lambda = \frac{h}{m_0 \times v}$.

Transmission Electron Microscope (TEM)

A type of electron microscope where a focused beam of electrons passes through an ultrathin prerez (section) of the sample.

Scanning Electron Microscope (SEM)

One of the two main types of electron microscopes mentioned alongside the transmission electron microscope.