Review of Main Points You are responsible for understanding all the exercises that we have done, everything that I have covered during the labs, and all the reading. Generally speaking, I have pulled the main points out of the reading and put them in this study guide. We also covered many minor points which are not covered here but are in the reading for each exercise.
Techniques used to prevent microbial contamination. The resolving power is the diameter of the smallest object visible.
The oil immersion objective requires the use of the immersion oil to bridge the space between the slide and the objective. The use of oil prevents the refraction of the light that would occur if the light waves passed through air.
Lens paper and alcohol for oil. To avoid breaking the slide 20 What is the advantage of using a differential stain compared to a simple stain? Differential stains distinguish different organisms on the basis of staining reactions. Information as to the Gram reaction of an isolate gives the physician direction as to which antibiotics would be most effective.
A negative stain is easy. No heat is required so distortion is minimal. This is particularly valuable in viewing spiral organisms, preserving their spiral morphology accurately.
Acid fast stain, endospore stain, simple stain and gram stain 23 Briefly explain why heat is needed as part of the method? Fixation will kill the cells and ensure that they will stay attached to the glass surface during staining. Endospores make it difficult for the stain to enter the bacteria so heat weakens this barrier.
As with acridine orange, Gram stain also shows a similar configuration of amebic cysts, such as polygonal shape with double wall. The double wall is discernible because of violet-blue color and active cysts usually show pink staining (Fig. 12 and Fig. 13). Lab management Random access gram stain automation: a review of current approaches R dardization, labor-efﬁciency, and through-put. Batch-design automated staining systems have provided some advantages over manual processing, such as increased throughput and reduced waste, but criti- Gram automated gram stain to manual gram stain. During such times, the Gram stain is the only technique available in the clinical microbiology laboratory for direct detection of fungi from these specimens. The presence of fungi should not be overlooked during the direct examination of the clinical specimens for bacteria.
Unable to clearly visualize the specimen, cell walls 25 What is step one when performing gram stain? A primary dye, crystal violet purple dyeacts as a simple stain staining all cells 26 What is step two when performing gram stain?
A mordant, Gram's iodinewhich complexes with the primary dye making it more difficult to wash out of the cells 27 What is step three when performing gram stain? A decolorizer, alcohol washwhich is the critical differential step, removing the primary dye from only certain cell types.
A counterstain, safraninwhich stains the decolorized cells a contrasting color. Specialty staining flagella - that uses mordant to thicken flagella, hanging drop slide - observing live organisms, using test media - motility is indicated by growth away from the line of inoculation 31 What is mordant?
It helps the first stain stick. It complexes with the primary dye making it more difficult to wash out of the cells 32 Why is it important to let the slide air dry before heat fixing?
Decolorizer is the critical differential step, removing the primary dye from only certain cell types.
Gram-positive cells have no lipid in cell walls, do not decolorize with ethanol or acetone, retain the crystal violet and appear purple.
Gram-negative call walls have a high lipid content, these decolorize and accept counterstain - safranin and appear red.
To allow movement of the specimen and not to flatten or squish the specimen.
The pure culture is necessary because there are many biochemical tests that are practical for the laboratory identification. The selection of which is determined by the morphology and Gram reaction of the isolate.
Special stains are for looking at structure, to color and isolate specific parts of microorganisms such as endospores and flagella, and to reveal presents of capsules.
Protect a cell from phagocytosis and allow it to adhere to other bacteria or surfaces such as tissue. Bacillus and Clostridium What test uses a Durham tube? What is the purpose of the Durham tube?Can simple staining identify more than the morphology and arrangement of bacteria?
Morphology, size, and arrangement are the only things that a simple stain can determine. What is the advantage of performing a gram stain over performing just a simple stain? such as insufficient chlorineCan detect a break in the distribution system by.
Gram staining, which is also referred to as the Gram’s method, is a scientific technique of staining that is used to differentiate the species of bacteria into 2 main groups, namely the gram-positive and the gram-negative bacteria. THE GERMICIDAL EFFECT OF STAINING SOLUTIONS GLADYS A.
ECKFELDT AND STEWART KOSER that such types as the diphtheria bacillus, the members of the colon- both as a simple stain and in the Gram method. It has the advantage of being stable and keeps well for a considerable. "What Is The Advantage Of The Gram Stain Over A Simple Stain Such As" Essays and Research Papers What Is The Advantage Of The Gram Stain Over A Simple Stain Such As Report Experiment Tittle Gram stain Experiment Date 24October Submission Date .
COURSE SYLLABUS Course Number: CLSC AR, BR, FR, GR, and HR. These labs are hybrid sections of the The major categories of microbial pathogens such as viruses, bacteria, fungi and State the advantage of the Gram-stain over a simple stain. Explain the uniqueness of the acid-fast bacteria cell wall.
The gram stain is a basic differential stain used to determine if a bacterial cell is gram positive or negative. Gram positive cells have a thick peptidoglycan layer that will trap the crystal violet iodine crystals and appear purple.