*Ocular Micrometry

posted Mar 31, 2014, 8:12 AM by Medical Parasitology Department   [ updated Apr 4, 2014, 6:07 AM ]


This training program will provide trainees with needed basic knowledge as well as extensive practical skills for bright field microscope (compound microscope) handling; and subsequently raise their abilities in microscope calibration & proper use of eyepiece micrometer to identify parasites especially ova & cysts.

Intended learning outcomes (ILOs):

1.    Understand the principles & precautions needed for proper handling of compound microscope.

2.    Perform a range of appropriate training in the lab to use different magnifications especially oil immersion lens for parasites identification.

3.    Work out with extensive training of: how to do microscope calibration?

4.    Use of ocular micrometer for measuring different parasitic stages that may be recovered from stool, urine and soil.

5.    Describe scientifically the important morphological features of recovered parasites

Importance of the program:

Correctly calibrated microscope and accurate measurement is crucial for parasitologist because size is an important characteristic for identification of different parasites. This program is essential in providing needed training in microscopy & practice of ocular micrometer for precise measurement of parasitic stages.

Program regulation and outline:

Each student is introduced with a short theoretical session on bright field microscope parts, proper care & performance, high lightening how to obtain best images with a special consideration for oil immersion lens. Practical sessions are performed on microscope calibration & using the micrometer for precise measurement.  Practical work is done through group work.  Practical sessions are concluded by discussions, demonstration and grading of the best performing group of the day. The trainees will be asked to incorporate in activity by applying the procedure to measure different parasitic stages (e.g. eggs of helminths, trophozoites & cysts of protozoa).

Main Topics:

- Introduction to compound Microscope.

-  Microscope parts, oil immersion lens.

-  How to get best image?

- What is micrometry?

- Why it is important to use it?

- Scientific description of microscopic images.

- How to do microscopic calibration (4X & 10X magnification)?   

  And to use micrometry in precise measurement?

- How to do microscopic calibration (40X & 100X  magnification)?

  And to use micrometry in precise measurement?

- Practical application on diversity of slides (helminthes, protozoa & arthropods).

- Practical Evaluation


Teaching Strategy:

The teaching strategy is based on extensive laboratory work. All students must be well trained on the method of calibration of different magnification powers using ocular micrometer. Then they must be as well skilled on using the ocular micrometer for measuring the size of recovered parasitic stages.

During the practical sessions trainees will do & practice all skills that have been taught.  Trainees are divided into groups of two or more according to their number.  At the end of the session, test results are compared and problems are discussed. 

Learning Time:

This program depends mainly on training sessions with few theoretical lectures and the learning time is designed as follows;

o    Lecture represents only 8.3% of the learning time (7.5 hours) and 36.7% (33 hours) is for tutorial & practical sessions (contact time is 45%). 

o   45 % (40.5 hours) is for self-directed training.

o   The remaining 10% (9 hours) is specified for assessment.


Depends mainly on practical achievement