Staining tray, wash bottles, inoculation loop microscopic glass slides, bunsen burner, blotting papers, microscopes. S ome staining techniques, such as the gram and ziel neelsen stains, although of great diagnostic value because of their differential staining properties for specific bacteria, reveal li ttle. Uk standards for microbiology investigations issued by the standards unit, public health england. Gram stain the previous lab introduced simple staining techniques that enable microbiologists to observe the morphological characteristics of bacteria. Chemically the cell wall is composed of peptidoglycan. Some staining techniques, such as the gram and ziel neelsen stains, although of great diagnostic value because of their differential staining properties for specific bacteria, reveal little. The previous lab introduced simple staining techniques that enable. Make a thin film of the material on a clean glass slide, using a. Microscopic slides endospores a stained preparation of bacillus subtilis showing endospores as uncoloured and the vegetative cell as. Sep 25, 2019 stains may be used to define and examine different types of microbes, various stages of cellular life e. The most common type of acid fast bacteria is mycobacteria. Different types of staining methods are used to make the cells and their internal.
Gram staining primary stain step 1 crystal violet is the primary stain used in the gram staining process it is not specific for gram positive cells and it stains everything the same color purple. These are of two types, namely direct and indirect staining. Staining techniques in some cases, staining is unnecessary, for example when microorganisms are very large or when motility is to be studied, and a drop of the microorganisms can be placed directly on the slide and observed. Staining tray, wash bottles, inoculation loop microscopic glass. Staining of bacterial cells objective to learn the techniques of smear preparation, gram staining, nigrosin staining and correlating the results of gram staining with koh test. This staining technique divides bacteria into two groups namely acidfast and non acidfast. Negatively charged acid radicals imparts color in eosin, acid fuchsine, malachite green, nigrosin. Gram staining is the common, important, and most used differential staining techniques in microbiology, which was introduced by danish bacteriologist hans christian gram in 1884. Some staining techniques, such as the gram and ziel neelsen stains, although. Wikimedia commons has media related to microbiology techniques.
By exploiting this phenomenon, an alternative gram staining technique has been developed. General microbiology morphology of bacterial cell, staining procedures for bacteria, culture media for bacteria, cultivation and isolation techniques for bacteria, preparation of pure cultures. Stain or dye is the synthetic chemical which is derived from nitrobenzene or aniline. This test differentiate the bacteria into gram positive and gram negative bacteria, which helps in the classification and differentiations of microorganisms. Several different types of staining procedure are known today which. Basic microbiologymlsbmic224 staining methods l 16, 17. Mycobacterium species resist the effect of the acid. Some staining techniques involve the application of only one dye to the. Introduction as bacteria consist of clear protoplasmic matter, differing but slightly in refractive index from the medium in which they are growing, it is difficult with the ordinary microscope, except when special methods of illumination are used, to set them in the unstained condition. Other differential staining methods include the endospore stain to identify endosporeforming bacteria, the acidfast stain to discriminate mycobacterium species.
Staining techniques in microbiology linkedin slideshare. Instruments used in microbiology lab with principle and uses. This list may not reflect recent changes learn more. Make a thin film of the material on a clean glass slide, using a sterile loop or swab for viscous specimens. Differential staining methods, which typically require more than one stain and several steps, are referred to as such because they permit the differentiation of cell types or cell structures. The most widely used staining procedure in microbiology is the gram stain, discovered by the danish scientist and physician hans christian joachim gram in 1884. Medical laboratory sciences medical bacteriology mls. There are a variety of staining methods like simple, differential and special staining that are used in labs to examine the bacteria. The peptidoglycan layer of gramnegative bacteria is covered by a membrane and is not labeled by the lectin. Heat or a lipid solvent is used to carry the first stain, carbolfuchsin, into the cells. Gram staining helps to identify bacterial pathogens in specimens and cultures by their gram reaction gram positive and gram negative and morphology coccirod. It determines the cell shape, size and arrangement of the microorganism.
Fluorescencelabeled wheat germ agglutinin binds specifically to nacetylglucosamine in the outer peptidoglycan layer of grampositive bacteria. Types of different staining techniques of microorganisms. This staining technique is used to demonstrate the presence of acid fast bacilli. It may be demonstrated by microdissection, reaction with specific antibodies, mechanical rupture of the cell, differential staining procedures or by electron microscopy. Mycobacterium and many nocardia species are called acidfast because. Composition, types and mechanism of staining composition. Molecular techniques in clinical microbiology molecular biology is the science of biomolecules. Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Gram staining procedure animation microbiology principle, procedure, interpretation duration. Microscopy refers to the practice that involves the use of a microscope for the purposes of observing small scale structures that cannot be viewed using the naked eye and often cell staining is necessary as s tructures are difficult to discern due to insufficient contrast. Stains are salts composed of a positive ion cation and a negative ion anion. The acidfast microorganisms retain the pinkred color because carbofuschsin is more soluble in the cell wall lipids than in acidalcohol. Staining, therefore, is of primary importance for the. Module morphology and classification of bacteria microbiology 10 notes stains.
The steps of the gram stain procedure are listed below and illustrated in table 1. The most commonly used instrument in the microbiology laboratory for the sterilization of media and glassware is the autoclave. It is a technique that is widely used for the examination of cells, tissues and cellular components. Blood is composed of the blood cells which accounts for 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid. Objectives to learn the technique of smear preparation. Cover different classification schemes for grouping bacteria, especially the use of the gram stain 2. Methylene blue, polychrome blue or carbol fuchsin to act as simple stain. This technique differentiates species of mycobacterium from other bacteria. Testing sensitivity to antimicrobial substances 21 2.
Gram staining is a differential staining technique that differentiates bacteria into two groups. Staining is a supplementary method that gives divergence to the microscopic image for better vision under the microscope. Basic techniques in biochemistry, microbiology and molecular biology pp 111116 cite as. Introduction observation of bacteria with conventional bright field microscopy yields relatively little useful information. Staining methods simple staining, negative staining, grams. This manual has been written for a righthanded person. Types of staining techniques used in microbiology and. Bacteria have nearly the same refractive index as water, therefore, when they. It was developed by danish microbiologist hans christian gram in 1884 as an effective method to distinguish between bacteria with different types of cell walls, and even today it remains one of the most frequently used staining techniques. Hematoxylin has a deep bluepurple color and stains nucleic acids by a complex, incompletely understood reaction. In microbiology, differential staining techniques are used more often than simple stains as a means of gathering information about bacteria. The instruments used in the microbiology labs include a bunch of different kinds of instruments required for a lot of different processes conducted within those laboratories. Gram stain is a very important differential staining techniques used in the initial characterization and classification of bacteria in microbiology. The word gram is always spelled with a capital, referring to hans christian gram, the inventor of gram staining gram staining principles gram staining is used to determine gram status to classify bacteria broadly.
In the laboratory, viruses have served as useful tools to better understand cellular mechanisms. Invivo staining is the process of dyeing living tissue in vivo means in life as contrasted to invitro staining. Basic microbiology notes online microbiology notes. Bacterial classification, structure and function introduction the purpose of this lecture is to introduce you to terminology used in microbiology. Different types of microscopes cell is the basic unit of life. Stains and dyes are frequently used in histology the study of tissue under the microscope and in the medical fields of histopathology, hematology, and cytopathology that focus on the study and diagnoses disease at a microscopic level.
Cell staining in microscopy types, techniques, preparations. Microbiological laboratory techniques clinical gate. Acknowledgments uk standards for microbiology investigations uk smis are developed under the auspices of public health england phe working in partnership with the national. It is one of the most important and widely used differential staining techniques in microbiology.
Already available was a staining method designed by robert. Different types of staining methods are used to make the cells and their internal structures more visible under the light microscope. Biochemical tests the sole purpose of biochemical test in microbiology is to differentiate between various classes of bacteria by studying their enzymatic activities. Microbiology module common staining technique microbiology 22 notes 2. Then the cells are washed with a dilute acidalcohol solution.
The following 61 pages are in this category, out of 61 total. Another differential stain technique is the acidfast technique. Microscopy using the microscope 22 stained preparations 23 making a smear 23 a simple stain 24 a differential stain. Types of staining techniques used in microbiology and their. Staining techniques in microbiology a presentation by g.
Stains may be used to define biological tissues highlighting. There are two types pili namely nonsex pili common pili eg. Gram stain protocols american society of microbiology. To perform this staining, it requires the use of a single stain only. The extremely minute size of this wonderful structure remained an obstacle for. Microbiology module common staining technique microbiology 24 notes indeterminate groups as well.
In microbiology the concept of staining is very important because it highlights the structures of microorganisms allowing them to be seen under a microscope simple and. Introduction to microbiology culture techniques youtube. This technique was introduced in 1884 by danish physician christian gram. Staining microscopic specimens microbiology lumen learning. Stains may be used to define and examine different types of microbes, various stages of cellular life e. Sep 19, 2016 gram staining procedure animation microbiology principle, procedure, interpretation duration.
A detailed discussion of the different types of physical and chemical methods of sterilization is provided in chapter 19 physical and chemical methods of control. Then apart from all this some other staining techniques are there for identification of fungus like lactophenol cotton blue staining, and many other techniques. To learn the techniques of gram staining, nigrosin staining and koh test. Cell staining in microscopy types, techniques, preparations and procedures. Heatfixed bacterial smears refer staining techniques in microbiology 1st edition by dr. The purpose of this lesson is to provide a general overview of laboratory techniques used in the. In microbiology the concept of staining is very important because it highlights the structures of microorganisms allowing them to be seen under a microscope. Methods of culturing microorganisms 3 five basic techniques 4 fig. To use and relate the gram stain to the study of bacterial cell morphology, and as an. Blood cells are the cells which are produced during hematopoiesis and found mainly in the blood. Staining simply means coloring of the micro organisms with the dye that emphasizes and elucidate different important structures of microorganisms including bacteria, virus, protozoa and etc. Different types of staining methods are used to make the cells and. Even though the term biomolecules includes all molecules such as proteins, fatty acids etc, it is refers to nucleic acid these days.
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