Bio 201 Unit 1: The Microscope

Parts of the microscope

Stand

The supporting framework of the microscope, which is composed of the base and arm

Base

The bottom portion of the microscope, the only part that touches the tabletop. Held with one hand underneath when carrying

Arm

The upper part of the stand, held by one hand when carrying

Stage

The large platform containing an opening near its center. Material to be studied is mounted on a glass slide and placed here for viewing

Mechanical stage

Mechanism for holding a slide on the stage

Mechanical stage arm

Holds slide in position on the stageM

Mechanical stage knobs

Move the slide in the x and y directions on the stage

Illuminator

Illuminates field of view when turned on

Light switch

Turns on the illuminator, found on the side of the microscopehR

Rheostat

Adjusts brightness of light from illuminator, usually found as a dial on the base or arm

Condenser

Focuses light from the illuminator. Should always be directly under the stage when first examining a specimen

Condenser knob

Focuses the condenser. Found under the stage

Diaphragm

Adjusts the amount of light from the illuminator. Its lever is attached to the condenser

Oculars

Lenses of the eyepieces. Magnify 10x

Pointer

Used to show another person a particular object seen in the field of view

Focusing knobs

Bring the field into proper focus. Must be adjusted for each eye and slid apart so the distance between them matches the distance between the user’s eyes

Coarse adjustment

The larger focusing knob. Moves the stage up and down to bring the object into focus. Should ONLY be used when the lowest power objective is in place

Fine adjustment

Smaller focusing knob. Moves the stage up and down to bring the specimen into focus on a smaller scale

Revolving nosepiece

Attached to three to four objectives. Must click into place

Scanning objective

Magnifies 4x (can be used with coarse focus)

Low power objective

Magnifies 10x

High power objective

Magnifies 40x (only use fine focus with this objective)

Oil immersion objective

Magnifies 100x. Oil is placed on the specimen and displaces the air between the lens and specimen

Depth of field

Distance range that is in focus at a given time