Grade 7 • The Historical Development of the Compound Light Microscope

Compound Microscope

An optical instrument that uses two or more lenses to magnify small objects.

Ocular Lens

The lens you look through at the top of the microscope, typically magnifying the object 5x or 10x.

Objective Lens

Lenses close to the specimen that gather light and magnify the image; can have varying magnifications such as 4x, 10x, 40x, and 100x.

Coarse Adjustment Knob

A large knob used to move the body tube up and down quickly to focus the specimen.

Fine Adjustment Knob

A smaller knob used to make precise adjustments to the focus of the specimen.

Stage

The flat platform where the slide with the specimen is placed.

Iris Diaphragm

Regulates the amount of light that passes through the specimen.

Rotating Nosepiece

The part of the microscope that holds the objective lenses and allows the user to switch between them.

Magnification

The process of enlarging the appearance of an object through the use of lenses.

Field of View (FOV)

The circular area visible through the microscope when looking through the ocular lens.

Natural Source of Light

Light that comes from the sun, used in microscopy to illuminate the specimen.

Artificial Source of Light

A light bulb used in microscopes to provide consistent illumination.

Antoine van Leeuwenhoek

A scientist known for creating powerful simple microscopes and observing microorganisms.

Cell

The basic structural unit of living organisms, first identified by Robert Hooke in cork.

Animalcules

Microscopic organisms observed by Leeuwenhoek in a drop of water.

Robert Hooke

An English scientist who improved microscope design and first described cells in 1665.

Dry Mount Slide

A slide prepared by placing a dry specimen on a glass slide and covering it with a coverslip.

Wet Mount Slide

A slide prepared by placing a specimen in liquid on a slide and covering it with a coverslip.

Total Magnification

Calculated by multiplying the magnification of the ocular lens by that of the objective lens.

Micron (μm)

A unit of measurement equal to one millionth of a meter, often used to measure small objects.

Dust Shield

A protective cover that prevents dust from settling on the microscope’s objective lenses.

Adjustments Screws

Move the objectives to bring the specimen into focus.

Specimen

An individual instance of a substance or organism being studied through the microscope.

Balsam

A type of medium used to prepare permanent microscope slides.

Staining

The process of applying dyes to a specimen to enhance contrast and visibility under a microscope.

Phase Contrast Microscope

A type of microscope that enhances contrast in transparent and colorless specimens without staining.

Electron Microscope

An advanced microscope that uses a beam of electrons to create highly magnified images of specimens.

Microscopy

The use of microscopes to view objects that are too small to be seen with the naked eye.

Resolution

The ability of a microscope to distinguish two close objects as separate; higher resolution indicates clearer images.

Cover Slip

A thin plastic or glass sheet placed over a specimen on a microscope slide to protect the specimen and the lens.

Light Microscope

A microscope that uses visible light to illuminate specimens and glass lenses to magnify the images.

Focal Plane

The plane in which the specimen is in focus within the microscope, affecting the clarity of the image.

Image Inversion

The phenomenon where the image seen through a microscope is upside down and reversed due to lens orientation.

Specimen Slide

A glass slide used to hold the specimen being observed under the microscope.

Microscopic Measurements

Measurements made on specimens observed under a microscope, often expressed in microns.

Aniline Dyes

A type of synthetic dye used in microscopy to stain biological tissues and enhance visual contrast.

Stroboscope

A device used to make a cyclically moving object appear to be slow-moving or stationary, often used in microscopy for motion analysis.

Microscope Anatomy

The various parts of a microscope, including lenses, stage, light sources, and adjustments, that work together to magnify specimens.

Condenser Lens

A lens that focuses light onto the specimen, enhancing illumination and contrast.

Working Distance

The distance between the lens and the slide or specimen when in focus, important for manipulating large objects.

Resolution Limit

The smallest distance between two points that can still be distinguished as separate entities under a microscope.

Depth of Field

The thickness of the specimen layer that appears in focus at one time, varying with magnification.

Field Diaphragm

An adjustable aperture that controls the diameter of the beam of light entering the microscope, improving clarity.

Parfocal Lenses

Lenses designed to stay in focus when switching between magnification powers, reducing the need for readjustment.

Fungal Spores

Reproductive structures produced by fungi, often observed under a microscope due to their small size.

Biofilm

A thin, slimy film of bacteria that adheres to a surface, commonly studied in microbiology using microscopy.

Bright Field Microscope

A type of light microscope that produces a dark image on a bright background, commonly used in biology.

Dark Field Microscope

A microscopy technique that enhances the contrast of unstained specimens, creating a bright image against a dark background.

Fluorescence Microscope

A type of microscope that uses fluorescence instead of transmitted light to create an image, allowing observation of specific cellular components.

Live Cell Imaging

A technique that allows the observation of living cells under a microscope in real-time.

Histology

The study of the microscopic structure of tissues, usually examined through tissue samples under a microscope.

Microtome

An instrument used to cut very thin slices of tissue for microscopic examination.

Coverslip Thickness

The thickness of the cover slip used in microscopy; affects light passage and resolution.

Objective Revolving Mechanism

The system in a microscope that allows the stage to rotate, enabling easy switching between objective lenses.

Microbial Colony

A visible cluster of microorganisms growing on a solid medium, often observed during microbiological studies.

Phase Contrast Objective Lens

Specialized objective lenses in phase contrast microscopes that enhance the contrast of transparent specimens.

Staining Techniques

Various methods used to prepare specimens for microscopy, including differential staining and immunohistochemistry.

Optical Resolution

The ability of a microscope to distinguish two separate points as distinct images, limited by the wavelength of light.

Light Source

The component of a microscope that illuminates the specimen, either through natural or artificial means.

Binocular Microscope

A microscope that offers two eyepieces for viewing, providing a three-dimensional view of the specimen.

Antifade Reagents

Substances used in microscopy to prevent photobleaching of fluorescent dyes during imaging.

Sample Preparation

The methods used to prepare a specimen for observation, including fixing, embedding, and sectioning.

Immunofluorescence

A technique used to visualize the presence and location of proteins or antigens in cells using fluorescent antibodies.

Tissue Staining

The application of dyes to tissue samples to enhance contrast and allow for better visualization under a microscope.

Microbial Morphology

The study of the form and structure of microorganisms, often observed through microscopy.

Scanning Electron Microscope (SEM)

A type of electron microscope that provides detailed three-dimensional images of surfaces by scanning the specimen.

Transmission Electron Microscope (TEM)

A type of electron microscope that transmits a beam of electrons through a specimen to form an image.

Slide Preparation Techniques

Methods employed to prepare a microscope slide, including mounting and covering samples for observation.

Quantitative Microscopy

The use of microscopy techniques to measure and quantify specific properties or features of samples.

Cell Viability Assays

Tests used to determine the health and functionality of cells typically observed through microscopy.

Dual-Channel Imaging

A microscopy technique involving two different fluorescent channels to observe multiple cellular components simultaneously.

Transmitted Light

The type of light that passes through a specimen, commonly used in light microscopy.

Image Contrast

The difference in brightness or color between an object and its background in an image.

Microbial Ecology

The study of microorganisms in their natural environments and their interactions with each other and their surroundings.

Specimen Handling

The proper techniques employed to collect and prepare specimens for microscopic examination.

Histopathology

The examination of tissue samples to study the manifestations of disease under a microscope.

Optical Microscopy

A microscopy technique that uses visible light and lenses to magnify specimens.

Digital Imaging

The process of capturing images of specimens using digital cameras attached to microscopes.

Polymerase Chain Reaction (PCR)

A molecular biology technique used to amplify DNA, often used in conjunction with microscopy.

Cellular Senescence

The process by which cells lose the ability to divide and grow, often observed under the microscope.

Staining Protocals

Standardized procedures for the application of dyes to specimens for enhanced visibility.

Bright Field Microscopy

A standard light microscopy technique that produces a dark image on a bright background.

Labeling Techniques

Methods used to tag specific structures within specimens for easy identification during microscopy.

Microbial Pathogenesis

The study of the mechanisms through which microorganisms cause disease, often observed through microscopy.

Cellular Architecture

The structural organization of cells as observed through microscopy.

Tissue Processing

The series of steps taken to prepare biological tissue for examination under a microscope.

Plasma Membrane Visualization

Methods used to observe and study the plasma membrane of cells using microscopy.

Imaging Modalities

Different techniques utilized in microscopy to enhance or gather various types of images from specimens.

Specimen Autofluorescence

Natural fluorescence of a specimen that can interfere with fluorescence microscopy.

Fixed Cell Microscopy

Observing cells that have been preserved and treated to maintain structure and allow for staining.

Cell Culture Techniques

Methods used to grow and maintain cells in controlled conditions for study under a microscope.

Optical Aberration

A defect in a lens system that causes image distortion, leading to a blurred or distorted image.

Virtual Image

An image formed by a microscope that cannot be projected onto a screen, as light rays do not actually converge.

Back Focal Length

The distance from the last lens of a microscope objective to the image plane where the image is formed.

Microbial Identification

The process of determining the species or type of microorganism present in a sample, often facilitated by microscopy.

Specimen Labeling

The practice of marking samples with identifying information to ensure proper tracking and study.

Chamber Slide

A slide with a built-in chamber used for observing live specimens, providing a controlled environment.

Inverted Microscope

A type of microscope that has its light source and objectives above the specimen stage, allowing for the observation of live specimens from below.

Cover Slip Technique

The method of applying a coverslip to a slide to protect the specimen and prevent evaporation.

Scanned Probe Microscopy (SPM)

A technique that involves scanning a probe over a sample's surface to obtain high-resolution images.