Act1 (Microscope)

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PRACTICUM REPORT OF BASIC OF BIOLOGY

USING THE MICROSCOPE

NAME : LULUK MUKARRAMAH

NIM : 140210103021

CLASS : A INTER BIOLOGY

STUDY PROGRAM OF BIOLOGY EDUCATION

DEPARTMENT OF MATHEMATIC AND SCIENCE

FACULTY OF TEACHER TRAINING AND EDUCATION

UNIVERSITY OF JEMBER

2014


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I. TITLE

Using The Microscope

II. OBJECTIVE

2.1. Introducing the components of microscope and how to use them

2.2. Determining wide the field of view from the microscope

2.3. Learn how to prepare materials that would be observe under microscope

III.BASIC TEORY

Microscope and its function

A microscope is a high precision optical instrument that uses a lens or a combination

of lenses to produce highly magnified images of small specimens or objects especially

when they are too small to be seen by the naked (unaided) eye. A light source is used

(either by mirrors or lamps) to make it easier to see the subject matter (Alan Hale, 2007:3). Three important parameters in microscopy are magnification, resolution, and contrast.

Magnification is the ratio of an objects image size to its real size. (c ampbell, 2008 : 95).

The function of microscope is to increase separation ability, so the object will larger and

possible to be observed.

Parts of microscope

Microscope divided into two big parts. That are optic part and non-optic part. Optic

part consist of objective lens, ocular lens, condenser lens, and mirror or other light source

as light controller. And non-optic part consist of base, stage, arm, coarse adjustment, fine

adjustment, tubular body, revolver, and diaphragm,

Objective lens is a lens that near with the object that will be observed. This lens form a

real, inverted, and magnified image. Ocular lens is lens near with eye or usually called as

eyepiece. It has function to form an illusion, inverted, and magnified image from objective

lens. The condenser functions to focus the light source on the specimen. It also eliminates

stray light and provides an uniform illumination.

A base is a part of microscope that has function to support the microscope so that it

can stand steady. Arm is the curved, upright structure which is attached to the base at the

inclination joint. Arm is the place to carry the microscope. A stage is the horizontal

platform which is attached to the arm. Stage is a place where the observation take place.

The stage contains a centrally located opening through which light can be reflected by the

mirror. The stage also has tow clips on it. The coarse adjustment consist of the larger pair

of discs which extend laterally from the upper part of arm. These may be used to

accomplish major changes of focusing distance. Fine adjustment consist of the smaller

pair of discs located just below the base. These may be turned to bring object into sharp


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focus. Tubular body is the cylindrical part of the microscope into which the ocular fits.

(Thomas, Jeanette. 1996 : 1) Under of the tubular body there is a place for objective lens

that can be rotated is called revolver. Diaphragm has function to control the light that will

enter to microscope by control the iris diaphragm lever.

How to use microscope

When doing an experiment or observation on laboratory, it is very important to know

how to use a microscope. In order to obtain the maximum separation ability, do the

following steps :

1. Use both hands to carry the microscope to your seat. Place the microscope on the

table in front of you and position yourself so that you are comfortably seated while

looking through the microscope.

2.

Place the microscope in the light, open the diaphragm until maximum.3.

Arrange the position of the flat/concave mirror, so that the condenser glass become

light.

4. Increase the condenser until maximum by rotating the condenser button

5.

Place a preparat on the stage of microscope

6. Pull down the tube microscope until objective lens nearly touching the cover glass.

7. Look through the ocular lens the preparat until focus by turning the regulator coarse

Note : when using a microscope , using a magnification of ocular and objective lens from

weak to coarse. Arrange slit diaphragm until adequate lighting.

The important things to Use Microscope :

1. Holding the microscope with one hand and the other hand to hold the foot microscope

2. The stage of microscope should be horizontal to keep from falling preparations

3. Clean the lens only with paper/special cloth to the lens (soft tissue)

4.

Get used to keep both eyes open when observing

5. After using the microscope, turn rough regulators on so there is a distance between the

objective lens with table microscope, arrange the position of the mirror in an upright

position. Clean the objective lens when struck oil emersion and clean up the table

microscope from dirt or spills medium using a tissue

6.

Store the microscope in cupboard with control temperature. (biology team lecturer,

2014 : 2-3)


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Putting the pieces of the letter q or b on the object glass

covering with the cover glass

Putting the preparat (object) of q or b letter on the stage

of microsco e.

Observing a preparat (object) using a magnification of the

ob ective lens weak

Looking and comparing the location of shadow with the

location of the object in ocular lens

drawing the shadow that has been compared with the

ob ect

sliding the preparat from left to right

Recording the result of observation

Moving the preparate up and down


IV.PRACTICAL METHOD

4.1TOOLS

a. Microscope

b. Object glass and cover glass

c.

pipettes

4.2MATERIALS

a. The cut of pepaer writing q and b

b.

Water

4.3 WORK METHOD

1. Observations piece of letter q or b

.


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2. Measuring an area of field of view

Putting the letter q or b in the object glass,

Looking in the left and back side of the praparat

table. There is a scale that determine of two axis.

Observing from ocular lens where is the location of

letter q or b

Making a mark of the result in the notebook by

seeing the scale number in preparate table

Moving the letter to the left side till the position

same with the right position.

Calculating a wide field of view by calculating the difference

between two points (diameter of field of view) with formula :

Known : L = wide field of view, = 3,14 /

, r = radius

Covering slowly with a cover glass

Observing the preparat (object) using a weak

magnification of objective lens

Putting the preparat (object) of q or b letter on

the stage of microscope.

then moving the preparat to the right till the limits of

letter visible



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V. OBSERVATION RESULT

From the experiment, we get a result :

1. Observations piece of letter q or b

1. Picture : letter b in microscope

become q

magnification = 40x

Description :

The image of letter b, in microscope

become letter q. The image form are

illusion, inverted, and magnified

the image moveoppositewith the object.

a. If the object move to the right side, the

image move to the left side,

b. If the object move to the left side, the

image move to the right side,c. if the object moving up, the image moving

down

d. if the object moving down the image

moving up.

Picture : letter q in microscope

become b

magnification = 40x

Description :

The image of letter q, in microscope

become letter b. The image form are

illusion, inverted, and magnified

the image moveoppositewith the object.

a. If the object move to the right side, the

image move to the left side,

b. If the object move to the left side, the

image move to the right side,

c. if the object moving up, the image moving

down

d. if the object moving down the image

moving up.

Image in

microscope

object

b

q

objectImage in

microscope


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2. Measuring the area of field of view

Objective lens : 4x

Ocular Lens : 10x

Magnification : 4x10 = 40x

VI.DISCUSSION

A microscope is an optical instrument or tool that usually used for observing a

specimen or object especially very small object that cant seen by the naked eyes.

Microscope is very important tool in biology field. It has several parts. Each part of

microscope has important role. For example objective lens that has function for forming

an image of an object, and then continued by an ocular lens. From the experiment, known

that the image of letter b in microscope become q, and letter q become b. But,

this image is not the mirror image. Because, if mirror image letter bbecome d and

letter q become p. This image is from lens image, that is objective lens, and ocular

lens. These lens is positive lens. Objective lens has character for forming a real, inverted,

and magnified image. And ocular lens has character for forming illusion, upright, and

magnified image.

When the light trough the object, the light will continued by objective lens getting an

image, this image become object for ocular lens, then ocular lens getting an image thatenter to our eyes. This image that seen on microscope. Objective lens make the image of

object become large and inverse too, then ocular lens make the image from objective lens

Left limits =

161 mm

Right limits =

165 mm

d = 4 mm so, r = 2 mm

L = r2

= 3,14 (2)2

= 12,56 mm

d on x axis= 165mm - 161mm= 4mm

Bottom limits = 11 mm

Upper limits = 16 mm

d on y axis = 16-11= 5 mm

d = 5 mm so, r = 2,5 mm

L = r2

= 3,14 (2,5)2

= 19,625 mm


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become larger. From this explanation, known that the magnification of microscope got

from the result of multiple magnification of ocular lens and objective lens. The

magnification that we use on this experiment is 10x from ocular lens, and 4x from

objective lens. So, the total magnification is 10x4=40x magnification. The final image that

we see in the microscope are illusion, inverse, and magnified image. it is the result of

reflection of objective and ocular lens.

The result from our observation about the movement of the object that had been see on

ocular lens, are :

a. If the object move to the right side, the image move to the left side,

b. If the object move to the left side, the image move to the right side,

c. if the object moving up, the image moving down

d. if the object moving down the image moving up.The conclusion from that result is that the movement of an image is opposite with the

object. The image that formed by object (inverted image ) influence the movement too.

Area of Field of view is an image area that seen from ocular lens. To know the area of

field of view moving forward, backward, left, and right the object and recording the left,

right, top, and bottom of limit of the object that can be seen on the scale of microscope.For

example when the object moved to the right side, the getting result is the left limit of the

object etc. Knowing the size of the field of view will enable to determine the size of the

object. The area of field of view get from these formula A= r2. is constant that the value

is 3,14 or 22/7. And r is the radius. From the experiment result, the right limit of the object

is 165 mm and left limit is 161 cm. The top limit is 16 cm and bottom limit is 11 cm. The

radius get from the difference between the right and left limits or top and bottom limit. The

result of radius from this experiment are d on x axis = 2 cm and d on y axis = 2,5 cm. and

the field of view for x axis = 12,56 mm and for y axis = 19,625 mm. The area of x and y

axis must be same because the image that showed by microscope has circle shape, and the

radius of circle always same. So, the field of view between x and y axis must be same.

However, the result of the area of field of view from this experiment are not same. This is

because a human error. when used the microscope, observer (me) used the microscope

careless. Besides that, the object that will be measured must be on the fix place, dont

make the object move because it will make the measurement is not accurate. Because the

accurate measuring can be very important when identifying an object. The stage or object

table must be horizontal.


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VII. CLOSING

7.1 CONCLUSION

A microscope is an optical instrument or tool that usually used for observing a

specimen or object especially very small object that cant seen by the naked eyes.

microscope has a function to increase separation ability so, we can see a small object.

Microscope has several parts that are objective lens, ocular lens, condenser lens, and

mirror or other light source as light controller, base, stage, arm, coarse adjustment, fine

adjustment, tubular body, revolver, and diaphragm, The image that formed on

microscope are illusion, inverse, and magnified image. the movement of an image is

opposite with the object. The area of field of view will gotten by using these formula

A=r2. The are of field of view must be same because the image that showed by

microscope has circle shape, and the radius of circle always same.7.2SUGGESTION

Always be careful when doing an experiment or observation, because the

carelessness will make the result of observation will not accurate. Should be careful in

using the tool or material and always pay attention on safety work in laboratory. Always

pay attention the explanation of the practical assistant when doing a practical work.


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BIBLIOGRAPHY

The lecturer team, 2014.Basic of Biology Student Lab Manual.Jember : University of Jember

Campbell, Neil.A., Jane B. Reece., 2008.Biology Eight Edition.England: Pearson Education

Inc.

Thomas, Jeanette. 1996.Laboratory exercise in the principles of Biology. USA : Burgess

Publishing company

Hale Alan. 2007.

http://www.celestron.com/c3/images/files/downloads/1211246798_microscopesinfo.pdf

[accessed on September 25, 2014].

Purnomo Bambang. 2008. www.geocities.ws/bpurnomo51/mik_files/mik2.pdf [accessed on

September 25, 2014]


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ATTACHMENTS

The picture of image of letter q on

microscope

The picture of image of letter b on

microscope


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Documents

Act1 (Microscope)