Cell Biology - Microscope Parts and Usage

The compound light microscope is a fundamental tool in cell biology used to magnify small specimens like plant and animal cells using visible light and glass lenses.

The Eyepiece (Ocular Lens) is the part you look through, which typically has a magnification of $10\times$.

Objective Lenses are the primary lenses used for magnification, usually found in three powers: Low ($4\times$), Medium ($10\times$), and High ($40\times$).

The Stage is the flat platform where the slide is placed, held in place by stage clips.

The Diaphragm (or Iris) controls the amount of light passing through the specimen to improve contrast.

The Coarse Adjustment Knob moves the stage significantly for initial focusing under low power, while the Fine Adjustment Knob is used for precise sharpening under high power.

Resolution is the ability of the microscope to distinguish between two separate points; higher resolution allows for clearer detail.

Biological specimens are often measured in micrometers ($\mu m$), where $1\ mm = 1000\ \mu m$ or $10^3\ \mu m$.