Course Content
Microscopes and Microscopy
MICROSCOPES AND MICROSCOPY OBJECTIVES By the end of this topic, the trainee should be able to: 1.Name various types of microscopes. 2.State the function of parts of a microscope. 3.Describe the use of compound light microscopes describe care and maintenance of compound microscopes. 4.Describe preparation of microscope slides
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The Cell
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define and explain meaning of terms. 2.State types of cells. 3.Describe the cell structure under the light microscope. 4.State the functions of cell organelles. 5.Describe the process of mitosis and meiosis. 6.Describe physiological processes of cells. 7.describe the techniques of cell isolation. 8.Describe the procedure of temporary cell preparation.
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Microorganisms
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Classify the major groups of microorganisms. 2.State the general characteristics of each group. 3.Explain their mode of nutrition and reproduction. 4.Describe culture media. 5.Describe culturing techniques for bacteria. 6.Describe methods for determining bacteria population. 7.Describe sterilization and disinfection techniques.
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Immunological Techniques
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Define terms. 2.Describe types of immunity. 3.Describe types of immune cells. 4.Describe the lymphoid organs and tissues. 5.Describe serological and immunological techniques.
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Herbarium Techniques
OBJECTIVES By the end of this topic , the trainee should be able to: 1.Explain terms 2.Describe importance of collecting and preserving herbarium specimens 3.Describe sources of herbarium specimens 4.Describe collection of herbarium specimens 5.Describe preservation of herbarium specimens 6.Describe display of herbarium specimens
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Museum Techniques
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Explain terms. 2.Describe importance of collecting and preserving museum specimens. 3.Describe sources of museum specimens. 4.Describe collection of museum specimens. 5.Describe preservation of museum specimens. 6.Describe display of museum specimens
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Vivarium Techniques
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Explain terms. 2.Describe importance of vivarium. 3.Describe essential features of a vivarium. 4.Describe construction of a vivarium. 5.Describe maintenance of a vivarium.
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Aquarium Techniques
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Explain terms. 2.Describe importance of aquariums. 3.Describe essential features of an aquarium tank. 4.Describe construction of an aquarium tank. 5.Describe maintenance of an aquarium tank.
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Laboratory Animals
OBJECTIVES The objective of this chapter is to give a better understanding of the technical requirements regarding handling, care and maintained of various laboratory animals In this chapter, we will; 1. Identify the various types of laboratory animals. 2.Discuss the general care and handling of laboratory animals. 3. Describe the various methods of restraining and humane killing laboratory animals 4.Discuss care of specific disease free (SPF)and Gnotobiotic animals
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Introduction to Ecology
OBJECTIVE By the end of this module, the trainee should be able to: 1.Explain terms. 2.Describe biotic and abiotic factors. 3.Explain adaptation of organisms to terrestrial and aquatic environment. 4.Describe the energy flow in ecosystem. 5.Explain estimation of population in ecosystem. 6.Describe influence of human activities on environment. 7.Describe basic biogeochemical cycles.
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Plant Anatomy and Physiology
OBJECTIVES By the end of this topic, the trainee should be able to: 1.Describe of plant parts and tissues. 2.Describe functions of various plant tissues. 3.Describe processes in plants .
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Biology Techniques For Science Laboratory Technicians
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GNOTOBIOTIC ANIMALS

Gnotobiotic animals, also known as germ-free animals, are laboratory animals that are completely free of all known and detectable microorganisms, including bacteria, viruses, fungi, and parasites. These animals are maintained in highly controlled and sterile environments to study the effects of specific microorganisms or to investigate the interactions between the host and the microbiota.

 The demonstration that laboratory animals can be reared and reproduce in a sterile environment made it possible to consider the more extensive use of this method. At present time, germ free rats, mice etc. are reared in many laboratories. Such animals were earlier called microbe-free or germ free animals but latter, these names were dropped and the name gnotobiotes was used. Gnotobiotic animals may be free from one or all forms of microbes:

  • Axenic gnotobiotesare those animals  that are totally free from all  microorganisms
  • Monoaxenic gnotobiotesare those animals  in which only  one particular type of microorganism have been eliminated.
  • Diaxenic gnotobiotesanimals are those that two types of microorganisms have been eliminate.
  • Heteroaxenicgnotobiotesare those  in which  microorganisms affecting the animals have been modified  while those animals having unmodified microbiota are called  conventional animals

Characteristics of Gnotobiotes

 Gnotobiotes have different characteristics from conventional animals. they reproduce equally well without microbes , the growth rate  is within the normal range  but however  the humoral and cellular defense  systems  is  not as developed as in conventional animals . However, both systems respond in a characteristic fashion following stimulation with antigens

Most gnotobiotes have distended  caecum which may be about 30% of the body weight .This can impair  reproduction in these animals  and may become twisted  in older rats and mice causing death . The enlarged caecum and bowels have high moisture content in gnotobiotes. These is mainly due to lack of microorganisms in the mecum that are responsible for the degradation of endogenous proteins, mucopolysacharides and other substances which are produced by cells lining the alimentary canal

Uses of Gnotobiotes.

The probable use  of  gnotobiotes include:

  • They may be used  in studies aimed at determining their development and reactions  in relation to a diet  that have been chemically defined
  • They also serve as sources of sterile organs and tissues for cultivation.
  • They provide good tools for research especially in studies involving the study of immune system.
  • When associated with one  or more pure cultures , they give an opportunity for  a more critical study  of the etiology of  infectious disease
  • Gnotobiotes give a more uniform susceptibility  than those that have been  previously infected
  • They are normally used in the production of colonies or herds  of animals  that are free from  one or more specific agent

Before maintaining or using gnotobiotes, it is necessary to confirm their biological status to ensure that they are free from all other living forms. Procedures for testing these should be modified from time to time to reduce incidences of undetected microorganisms. New methods should be used as soon as they are approved.

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