To learn the techniques of gram staining, nigrosin staining and koh test. The course only covers aerobic microorganisms, those that grow in the presence of oxygen. The gram stain is one of the most important methods used in the clinical microbiology laboratory. Gram staining technique is the widely used differential staining technique in bacteriology. Learn microbiology 1 lab practical staining with free interactive flashcards. The reason why it is so much popular among the medical and prenursing students is that of its clear presentation of intricate microbiology topics and comprehensiveness. This stain, originally developed to help distinguish bacteria from host cells in tissue, has evolved as a key assay to help clinicians decide which antibiotics should be used to treat infections, given that gram. Bacterial classification, structure and function introduction the purpose of this lecture is to introduce you to terminology used in microbiology. None of the classes of major chemical constituents of the walls of bacteria and yeasts is exclusive to organisms which give a gram positive reaction. Special stains have been developed over time for identifying bacteria species, differentiating them morphologically, and even characterizing there very special features. Protocols for using the gram stains in the microbiology laboratory.
Objectives to learn the technique of smear preparation. Explore ideas for your next experiment and discover fun chemistry tutorials. A free online atlas with important points and facts to help you remember and learn all aspects and areas of microbiology. Science prof online offers free fullydeveloped science curricula, including the virtual microbiology classroom vmc, a 15week course featured on this page. Occurrence of a phosphoric ester in certain bacteria. Cover different classification schemes for grouping bacteria, especially the use of the gram stain 2. From the teaching laboratory to the clinical microbiology laboratory, one of the bestknown tools to study microbes is the gram stain. The gram stain, the most widely used staining procedure in bacteriology, is a complex and differential staining procedure.
Types of staining techniques used in microbiology and. Stains, or dyes, contain salts made up of a positive ion and a negative ion. Medical microbiology microscopic slides and media head of microbiology department and laboratory medical immunology. Gram staining helps to identify bacterial pathogens in specimens and cultures by their gram reaction gram positive and gram negative and morphology coccirod. Gram stain primary test where gram positive and gram negative terms come from. Microbiology lecture 2 gram positive and gram negative. The gram stain is a differential method of staining used to assign bacteria to one of two groups gram positive and gram negative based on the properties of their cell walls. Depending on the type of dye, the positive or the negative ion may be the chromophore the colored ion. The procedure is named for the person who developed the technique, danish bacteriologist hans christian gram. This was developed in 1884 by a danish bacteriologist, hans christian gram. Microbiology mcq question paper pdf in this article i have provided multiple choice questions mcqs of microbiology in pdf which is very important for those who are preparing for competitive exams like neet, gpat, aiims. Bacterial cell morphology, staining reactions, classification of bacteria.
Review of medical microbiology and immunology 15th edition. The latter are characterized by high lipid contents. Asm journals are the most prominent publications in the field, delivering uptodate and authoritative coverage of both basic and clinical microbiology. Basic microbiology lab reporting gram staining staining. In addition to fixation, staining is almost always applied to color certain features of a specimen before examining it under a light microscope. Testing sensitivity to antimicrobial substances 21 2. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Today, in this article, we are going to share with you microbiology. This test differentiate the bacteria into gram positive and gram negative bacteria, which helps in the classification and differentiations of microorganisms. It covers both the basic and clinical aspects of bacteriology, virology, mycology, parasitology, and immunology and also discusses important infectious diseases using an.
Gram staining is a differential staining technique that differentiates bacteria into two groups. The filter gram stain was approximately 100fold more sensitive than the slide gram stain. Walls of gram positive bacteria are richer in mucopeptide than are those of gram negative bacteria. Actinomyces israelii gram stain gram positive bacteria that form long, branching. The gram stain and differential staining journal of. Gram stain or gram staining, also called gram s method, is a method of staining used to distinguish and classify bacterial species into two large groups. The relation of the gram stain to the cell wall and the ribonucleic acid content of the cell. The gram stain is almost always the first step in the identification of a bacterial organism, while gram staining is a valuable. Through a series of staining and decolorization steps, organisms in the domain bacteria are differentiated according to cell wall composition. Microbiology lecture 2 gram positive and gram negative bacteria gram staining principle this second microbiology lecture will explain the properties of gram positive and gram. The course only covers aerobic microorganisms, those.
Gram stain is a very important differential staining techniques used in the initial characterization and classification of bacteria in microbiology. 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. Protocol mybook is a cheap paperback edition of the original book and will be sold at uniform, low price. Microbiology overview interpretation of preliminary microbiology data gram positive cocci gram negative cocci aerobic in clusters.
Gram staining detects a fundamental difference in the cell wall composition of bacteria. Choose from 500 different sets of microbiology 1 lab practical staining flashcards on quizlet. The name comes from the danish bacteriologist hans christian gram, who developed the technique. Microscopy using the microscope 22 stained preparations 23 making a smear 23 a simple stain 24 a differential stain. Free microbiology photos of gram stained slides viewed through compound microscope and with naked eye. This elearning course familiarizes laboratory professionals with how to read a gram stain, colonial characteristics, and biochemical tests used to identify gram positive microorganisms as well as commonly used testing algorithms. Kits are available commercially, or formulas for reagents are listed in appendix b. It is used for initial assessment of specimens prior to culture and is an important step in the workup and identification of pathogens isolated from clinical specimens. The gram staining technique differentiates the mixed culture cells into two terms as gram positive bacteria and gram. The most common stain being gram staining, acidfast staining, endospore staining. Each of these stains aims at identifying and characterizing bacteria based on their morphologies. It is also known as gram staining or gram s method. While many traditional lab manuals are lengthy and comprehensive, descriptions of the labs in this manual are kept minimal to encourage students to further research the procedures and results on their own. Gram stain tutorial the wet prep microscopy use, care and cleaning.
Gram stain results, organism, likelihood that the culture was contaminated based on the organisms that are isolated, number of organisms that grow, and patient gender. Oral microbiology bacteria causing inflammations and abscesses. To use and relate the gram stain to the study of bacterial cell morphology, and as an. Gram positive and gram negative, based on the differences of the chemical and physical properties of the cell wall. 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. Clostridium louisiana department of health and hospitals the common pathogens of this genus are gram positive anaerobes.