DB014 Exp1 Revision

DB014 Experiment 1 Revision

Microscopy

​Compound Light Microscope

• ​The microscope used in our syllabus is called the compound light microscope.

• ​a

• ​It's named compound because it uses two types of lenses to magnify objects, which are the ocular & objective lenses.

​Parts of a compound microscope:

• ​The backbone of the microscope

• ​This is where you should hold the microscope with one hand when transporting it.

• The other hand is used to support the base of the microscope.

​Arm

​Parts of a compound microscope:

• ​Placed on the eyepiece

• ​Can be adjusted sideways to fit the distance between eyes

• ​Normally has 10x magnification power

​Ocular lens

​Parts of a compound microscope:

• ​Attached to the nose piece.

• ​A set of 4 lenses with different magnification power.

• ​Each magnification power is colour-coded

​

1. ​Scanning lens: 4x (red)

2. Low power lens: ​10x (yellow)

3. ​High power lens: 40x (blue)

4. ​Oil immersion lens: 100x (white)

​Objective lens

​Parts of a compound microscope:

• ​This is where the set of objective lenses are attached to.

• ​Rotate this part when you want to change the objective lens power

​Nose piece

​Parts of a compound microscope:

• Modifies the clarity of observed image​ by adjusting the height of the stage

• ​Should only be used with the scanning objective lens

​Coarse adjustment knob

​Parts of a compound microscope:

• ​Located within the coarse knob

• ​Used to obtain sharp and clear images of specimen

• ​Can be used with any objective lenses

​Fine adjustment knob

​Parts of a compound microscope:

• ​Specimen on a slide is placed on the stage for observation

• ​Stage clip is used to secure slides

• ​On the stage, slide can be adjusted horizontally or vertically using the stage adjustment knob

​Stage

​Parts of a compound microscope:

• ​Acts as the light source

• ​Brightness can adjusted using the adjustment scroll on the side of the microscope

Illumination

​Parts of a compound microscope:

• ​Placed underneath the stage, directly under the specimen

• ​It gathers the light wavelength coming from the illuminator and concentrates it

• ​It functions the same way as the iris in human's eyes

Condenser

Next: Parts of Microscopes Short Quizzes​

​

Multiple Choice

What is A?

• Revolving Nose Piece

• Ocular Lens

• Objective Lens

• Light

Multiple Choice

What is B?

• Light

• Arm

• Base

• Revolving Nose Piece

Multiple Choice

What is C?

• Ocular Lens

• Stage

• Objective Lens

• Light

Multiple Choice

What is D?

• Stage Clips

• Light

• Coarse Adjustment Knobs

• Stage

Multiple Choice

What is E?

• Light

• Diaphragm

• Fine Adjustment Knobs

• Ocular Lens

Multiple Choice

What is F?

• Stage

• Arm

• Base

• Fine Adjustment Knobs

Multiple Choice

What is K?

• Light

• Revolving Nose Piece

• Diaphragm

• Arm

Multiple Choice

What is I?

• Fine Adjustment Knob

• Arm

• Coarse Adjustment Knobs

• Objective Lens

Multiple Choice

What is H?

• Fine Adjustment Knobs

• Ocular Lens

• Diaphragm

• Coarse Adjustment Knobs

Multiple Choice

What is G?

• Objective Lens

• Base

• Revolving Nose Piece

• Arm

Multiple Choice

What part of the microscope do you look through?

• Objective Lenses

• Stage

• Ocular Lens

• Base

Multiple Choice

Which part of the microscope do you rotate to change the objective lens?

• Diaphragm

• Stage

• Stage Clips

• Revolving Nose Piece

Multiple Choice

Which part of the microscope holds the slide in place?

• The Stage clips

• The Arm

• The Stage

• The Diaphragm

Multiple Choice

Which part of the microscope moves the stage up and down to help focus the image?

• Adjustment knobs

• Objective Lens

• Stage

• Diaphragm

Multiple Choice

What lens has a magnification power of 40x

• Ocular lens

• Low power objective

• Mid power objective

• High power objective

Multiple Choice

Which lens has a magnification power of 4x?

• Scanning objective lens

• Low power objective lens

• High power objective lens

• Oil immersion objective lens

Multiple Choice

Which lens has a magnification power of 10x?

• Scanning objective lens

• Low power objective lens

• High power objective lens

• Oil immersion objective lens

Multiple Choice

Which lens has a magnification power of 100x?

• Scanning objective lens

• Low power objective lens

• High power objective lens

• Oil immersion objective lens

Calculating actual magnification​

​

​Actual magnification

Every observed image has been magnified to a degree - depending on the magnification power of the lenses used.

​

Compound microscope has two sets of lenses, therefore both must be taken into account.

​

​Actual magnification = ocular lens x objective lens

​

​Example:

​A specimen observed using the 10x objective lens on a microscope with 10x ocular lens magnification would produce an image that is 100x larger.

Multiple Choice

An image is observed using the 10x objective lens.

What is its actual magnification?

• 40x

• 100x

• 400x

• 1000x