Laboratory Methods in Microbiology

W. F. Harrigan, Margaret E. McCance

• Publisher: Academic Press
• Year: 2014
• Print ISBN: 9781483232058
• eBook ISBN: 9781483274348
• Topic: Biological Sciences
• Subtopic: Immunology
• Index: Biological Sciences

Laboratory Methods in Microbiology is a laboratory manual based on the experience of the authors over several years in devising and organizing practical classes in microbiology to meet the requirements of students following courses in microbiology at the West of Scotland Agricultural College. The primary object of the manual is to provide a laboratory handbook for use by students following food science, dairying, agriculture and allied courses to degree and diploma level, in addition to being of value to students reading microbiology or general bacteriology. It is hoped that laboratory workers in the food manufacturing and dairying industries will find the book useful in the microbiological aspects of quality control and production development. The book is organized into two parts. Part I is concerned with basic methods in microbiology and would normally form the basis of a first year course. Abbreviated recipes and formulations for a number of typical media and reagents are included where appropriate, so that the principles involved are more readily apparent. Part II consists of an extension of these basic methods into microbiology as applied in the food manufacturing, dairying and allied industries. In this part, the methods in current use are given in addition to, or in place of, the ""classical"" or conventional techniques.

Part I

BASIC METHODS

Outline

Chapter 1: GENERAL NOTES ON LABORATORY PROCEDURE

Chapter 2: LABORATORY REPORTS

Chapter 3: PROCEDURE FOR THE USE OF A MICROSCOPE WITH AN OIL-IMMERSION OBJECTIVE

Chapter 4: EXAMINATION OF CULTURES FOR MOTILITY BY “HANGING DROP” PREPARATIONS

Chapter 5: STAINING METHODS

Chapter 6: CULTIVATION OF MICRO-ORGANISMS

Chapter 7: THE DESCRIPTION OF THE MORPHOLOGICAL AND CULTURAL CHARACTERISTICS OF AN ORGANISM

Chapter 8: PLATE CULTURES

Chapter 9: DETERMINATION OF THE NUMBER OF VIABLE ORGANISMS IN A SAMPLE

Chapter 10: DETERMINATION OF THE TOTAL NUMBER OF ORGANISMS IN A SAMPLE

Chapter 11: STATISTICAL METHODS FOR THE SELECTION AND EXAMINATION OF MICROBIAL COLONIES

Chapter 12: COMPOSITION OF CULTURE MEDIA

Chapter 13: METHODS OF ANAEROBIC CULTURE

Chapter 14: CULTIVATION IN A CARBON DIOXIDE-ENRICHED ATMOSPHERE

Chapter 15: BIOCHEMICAL TESTS FOR BACTERIA

Chapter 16: CLEANING OF GLASSWARE AND APPARATUS

Chapter 17: STERILIZATION

Chapter 18: LABORATORY EVALUATION OF DISINFECTANTS

Chapter 19: SEROLOGICAL METHODS

Chapter 20: MOULDS AND YEASTS

Chapter 21: THE ISOLATION OF BACTERIOPHAGE

GENERAL NOTES ON LABORATORY PROCEDURE

It should be assumed that the bacteria with which you are working are capable of producing disease. Great care should therefore be taken in handling cultures, slides, and all material that may have been in contact with living micro-organisms. The following precautions should always be taken:

1. Microscope slides and coverslips should be discarded into jars of disinfectant solution. Used pipettes should be placed in polythene pipette jars containing disinfectant solution.

2. Labels should not be moistened with the tongue.

3. Accidents such as spilled cultures, cuts or abrasions should be reported to the laboratory demonstrator. It must be emphasized that the absence of breakage does not imply that no danger exists, since the dropping of a Petri-dish culture, for example, will result in the release of a “bacterial aerosol” into the atmosphere even if the dish does not break. The danger of creating contaminated aerosols by careless handling is much underestimated.

4. Laboratory coats should be worn.

5. Do not eat, drink or smoke in the laboratory.

6. Sterilize inoculating needles and loops before and after use by heating in the Bunsen flame until red hot. Avoid spattering of material by gradually introducing the instrument into the Bunsen flame.

7. Test-tubes containing cultures should always be kept upright in test-tube racks. Never lay the test-tubes on the bench-top.

8. Wash your hands thoroughly before leaving the laboratory.

Attempt to plan your work in the laboratory so that the most benefit is obtained from the time available. For example, if microscopic counts are to be carried out on a sample in addition to viable counts, the preparation of dried and stained smears and the preparation of viable counts can usually be carried out concurrently rather than consecutively.

LABORATORY REPORTS

All work carried out in the laboratory should be written up fully in a laboratory report book. If you do not record work in the laboratory report book at the time it is performed, very full notes should be taken in a laboratory records book. It cannot be emphasized too strongly that the notes made in a laboratory records book should be as full as possible. Often, observations are made during the course of an experiment which are not required in a report bearing on a particular aspect of the work. It may be that, at a much later date, these apparently superfluous observations will prove extremely useful. This is particularly the case when a research project is being carried out, since a rather narrow line must frequently be followed, with the necessity at the time to ignore many observations and results which suggest follow-up experiments.

It is always a good policy not to destroy these laboratory records books, but to keep them for some time after writing up the laboratory reports. In the quality control laboratory this will enable reports to be substantiated to a certain extent should the need arise. In this connection, it is perhaps advisable to use bound books, not loose-leaf folders, and to date all entries.

Reports of experiments and tests carried out should be written up in a standard form. For example:

1. Title of the experiment or test performed and the date.

2. The object of the experiment or test.

3. An outline of the methods used and, if stock cultures were employed, the names and brief descriptions of the organisms. Where the methods depart from those detailed in the manual of methods customarily used, they must be described in full.

4. A description of the results obtained. This is often best given as a written report with tables or graphs used to clarify the results, but in some cases tables with any necessary footnotes may be more suitably employed to give the results obtained. If class or group experiments are performed, all the results should be recorded.

5. A statement of the conclusions which can be drawn from the results.

PROCEDURE FOR THE USE OF A MICROSCOPE WITH AN OIL-IMMERSION OBJECTIVE

1. First ensure that objectives, eye-piece, condenser and mirror are clean, removing a...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• PREFACE
• Part I: BASIC METHODS
• Part II: TECHNIQUES IN APPLIED MICROBIOLOGY
• APPENDIX 1: SCHEMES FOR THE IDENTIFICATION OF MICRO-ORGANISMS
• APPENDIX 2: RECIPES FOR STAINS, REAGENTS AND MEDIA
• APPENDIX 3: PROBABILITY TABLES FOR THE ESTIMATION OF BACTERIAL NUMBERS BY THE DILUTION TUBE TECHNIQUE
• SELECTED BIBLIOGRAPHY
• REFERENCES
• AUTHOR INDEX
• SUBJECT INDEX