EXPERIMENT 1 DB014

BIOLOGY DB014

EXPERIMENT
1

BASIC TECHNIQUES IN
MICROSCOPY

DB014 Lab Manual

EXPERIMENT 1: BASIC TECHNIQUES IN MICROSCOPY

Course Learning Objective: Conduct basic biology laboratory work on
microscopy, tissues, genetics information, pollen germination and plant
growth by applying manipulative skills.
(P3, CLO 2, PLO 2, MQF LOD 2)

Learning Outcomes:
At the end of this lesson, students should be able to:
i. Handle microscope properly
ii. Obtain accurate images.
iii. Calculate the actual magnification.

Student Learning Time (SLT):

Face-to-face Non face-to-face

2 hours 0

Experiment 1.1: Handling Microscope Properly

Before doing the following experiments, you must read and understand
the basic techniques of using a microscope. Refer to Introduction to
Microscopy.

Apparatus

Compound microscope

Experiment 1.2: To obtain accurate images 1

Apparatus

Compound microscope

Materials
‘e’ prepared slide
Cross threads prepared slide (3 colours)
Transparent ruler (10 mm size)
Updated: 20/05/2020

DB014 Lab Manual

Procedures and Observation

Images under the microscope

1. Observe the ‘e’, cross threads and transparent ruler prepared slide
using the 4x objective lens.

2. What do you observe using the 4x objective lens? Draw what you
have observed.

3. What do you observe using the 10x objective lens? Draw what you
have observed.

Experiment 1.3: Magnification

Procedures and Observation

1. Determine the actual magnification of a specimen by using the
formula below.

Magnification power x Magnification
Actual magnification = of objective lens a power
g of ocular lens

2. Calculate the actual magnification in Table 1.1. n
i

Table 1.1 Actual magnification of a sfpecimen
i

Actual magnification c
a

Magnification Magnification power of obtjective lens
power of ocular i

lens 4x 10x 40xo 100x
n

10x p
o
w
e
r

Updated: 20/05/2020 o
f2

o
b
j
e
c

DB014 Lab Manual

Questions

Part A: Handling microscope properly.

1. A microscope is called a compound microscope when it consists
of more than one set of …………………………………

2. Condenser and iris diaphragm are useful to coordinate
…………………………………………...

3. Based on laboratory practices, what do you use to clean the
microscope lenses?

4. While observing a moving microorganism under a microscope,
you found that the organism has moved out of the field of view
to the right. In order to keep observing the microorganism, which
direction do you move your slide (right/left)?

5. How do you adjust the slide when the specimen is out of the field
of view to the top?

Part B: To obtain accurate image

1. Which is the shortest objective lens?
2. Which objective lens should you use when you begin to focus a

specimen?
3. Which objective lens should be in position before you store a

microscope?
4. Which objective lens will still remain in focus when placed at the

longest working distance from the specimen?
5. When using an ocular lens with 10x magnification power, which

objective lens should be used to obtain the following actual
magnification?
(a) 100 times of its diameter
(b) 1000 times of its diameter

Updated: 20/05/2020 3