Rinsing slide after application of crystal violet counterstain. Nearly all other genera of bacteria are nonacid fast. Paul ehrlich is the first to describe the acid fast properties of the bacterium. Acid fast stain free microbiology images from science prof. Start studying lab 5 acid fast stain questionsanswers. Microorganisms can be grouped on the basis of their need for oxygen to grow. Commons is a freely licensed media file repository.
Emmajane doan microbiological maureen lyons 110415 lab report acidfast staining introduction. Most common of the acid fast staining techniques is the ziehlneelsen technique. Acid fastness in the property of certain bacteria mycobacteria, their structures spores or protozoal forms oocyts. In the acidfast staining method, acidfast bacteria such as mycobacterium are not decolorized by acidalcohol and are therefore stained pink to red by the basic fuchsine. Acidfast staining acidfast stain is a differential stain. The quiz and worksheet help you see what type of knowledge you have about acid fast bacteria and their characteristics.
Detection of acid fast bacilli afb in stained and acid washed smears examined microscopically may provide the initial bacteriologic evidence of the. Its main application is in the staining and demonstration of acid fast bacilli in sputum smears. Acidfast staining lab report emmajane doan microbiological. Acid fast staining differentiates acid fast bacteria from non acid fast bacteria based on the mycolic acid content in the cell wall. The waxy substance is called mycolic acid and resists decolorization by acid alcohol. Once stained as part of a sample, these organisms can resist the acid andor ethanolbased decolorization procedures common in many staining protocols, hence the name. Summary and explanation the microscopic acid fast staining technique is one of the earliest methods used for detection of the tubercle bacillus. I had trouble with figuring out whether it is acid fast. Acidfast microorganisms will retain this dye and appear red. Scope this instruction describes the ziehlneelsen zn staining technique for the detection of acidfast bacilli afb by microscopy. The acidfast genera have lipoidal mycolic acid in their cell walls. Acid fast staining in tuberculosis slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
Kinyoun or ziehlneelson carbolfuchsin staining procedure to differentiate acid fast bacteria from nonacid fast bacteria. Acid fast staining in tuberculosis linkedin slideshare. Acid fast stain mycobacterium and many nocardia species are called acid fast because during an acid fast staining procedure they retain the primary dye carbol fuchsin despite decolorization with the powerful solvent acid alcohol 95% ethanol with 3% hcl. Jun 12, 2018 the main aim of this staining is to differentiate bacteria into acid fast group and non acid fast groups. The evaluator needs to have a good understanding of acid fast bacilli afb smear microscopy and good laboratory practice glp. Hence, these bacteria are called acid fast bacilli and the staining method is called acid fast staining.
Such cells are thus termed acid fast in that the cell will hold the stain fast in the presence of the acidic decolorizing agent. Acidfast stain principle, procedure, interpretation and examples. In the acid fast staining method, acid fast bacteria such as mycobacterium are not decolorized by acid alcohol and are therefore stained pink to red by the basic fuchsine. Organisms exhibiting the property of acid fastness, once stained, are not easily decolourized by alcohol. Modified kinyouns acidfast stain cold preanalytical considerations i. Microscopic examination of tissues or of sputum stained by the acid fast staining procedure is an aid in the diagnosis of tuberculosis. Acidfast stain kit afb staining for mycobacteria and. Paul ehrlich is the first to describe the acidfast properties of the bacterium. Examine under high dry magnification and verified under oil immersion. Organisms exhibiting the property of acidfastness, once stained, are not easily decolourized by alcohol. Summary and explanation the microscopic acidfast staining technique is one of the earliest methods used for detection of the tubercle bacillus.
Sep 24, 2009 acid fast stains detect organisms with waxy cell walls. These were subjected to various modifications of kinyouns af staining cold technique using 1% acid alcohol, 3% acid alcohol, 1% h 2 so 4, and 10% h 2 so 4 with methylene blue as the counterstain. In the zn acidfast stain is a fairly vigorous staining procedure using carbolfuchsin karbalfyukshun as the main stain and methylene blue as a counter stain other counter stains may be used but we will ignore them for simplicity. Oct 28, 2015 a video module on concept of acid fast staining. Kinyoun or ziehlneelson carbolfuchsin staining procedure to differentiate acidfast bacteria from nonacidfast bacteria. The main aim of this staining is to differentiate bacteria into acid fast group and nonacid fast groups. Tb assay 2 article pdf available in indian journal of medical microbiology 254. The ziehl neelsen stain was first described by two german doctors.
When stain is applied, all cells including hard to stain acid fast, are colored red. Jul 24, 2008 acid fast stain and gram stain question. Test your knowledge with the acid fast staining lab 9 quiz. In microbiology class today, we had to figure out if an unknown is gram positive or negative, their morphology, shape, acid fast or non acid fast, and spore former or not. Acidfast stain principle, procedure, interpretation and. Two acidfast genera that are important as human pathogens are mycobacterium and nocardia. Emmajane doan microbiological maureen lyons 110415 lab report acid fast staining introduction. Acid fast staining was introduced by ehrlich in 1882. Errors done in the decolorizing stage of the acid fast stain could have caused acid fast bacteria to appear nonacid fast. Acidfast stain mycobacterium and many nocardia species are called acidfast because during an acidfast staining procedure they retain the primary dye carbol fuchsin despite decolorization with the powerful solvent acidalcohol 95% ethanol with 3% hcl. The acid fast stain robert koch was the first person to isolate and identify mycobacterium tuberculosis from a patient with tuberculosis. He developed a stain for the bacterium, although it was not very effective for visualizing this slender bacillus.
Cells that retain the counterstain after undergoing acidfast staining are considered to be. They can be stained by aniline dyes using drastic measures such as application of heat and. The next step is to decolorize all tissue components except the acid fast bacilli. Based on the kinyoun modified staining technique, the acid fast stain is a very useful tool for differentiating acid fast bacteria afb, such as mycobacterium spp. Because nonacidfast bacteria such as staphylococcus are decolorized by the acidalcohol, a. The acid fast stain is a differential stain used to identify acid fast organisms such as members of the genus mycobacterium acid fast organisms are characterized by waxlike, nearly impermeable cell walls. This property is possessed by few bacteria other than mycobacterium. If my acid fast species came out blue, instead of fuchsia, then it means that the species i used didnt have a cell wall however staphylococcus auerus for acid fast stained blue meaning it was negative, that it didnt have a cell wall nor mycolic acid. The name of the dye carbol fuschin comes from the phenol and basic fuschin ingredients of the stain. An evaluative study priya p lunawat munot, 1 amit a mhapuskar, 2 s m ganvir, 3 vinay k hazarey, 4 madhavi a mhapuskar, 5, 6 and dinraj kulkarni 7. Microscopic examination of tissues or of sputum stained by the acidfast staining procedure is an aid in the diagnosis of tuberculosis. Evaluation of different modifications of acidfast staining. Acid fast smear evaluation and reportinga report no.
The evaluator needs to have a good understanding of acidfast bacilli afb smear microscopy and good laboratory practice glp. This method is used for those microorganisms which are not staining by simple or gram staining method, particularly the member of genus mycobacterium, are resistant and can only be visualized by acid fast staining. It is named for two german doctors who modified the stain. If you continue browsing the site, you agree to the use of cookies on this website. Once stained as part of a sample, these organisms can resist the acid andor.
This technique is useful for the identification of oocysts of the coccidian species cryptosporidium, cystoisospora, and cyclospora, which may be difficult to detect with routine stains such as trichrome. Acid fastness is a physical property of certain bacterial and eukaryotic cells, as well as some subcellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. The acidfast stain is useful in the diagnosis of what two. This is the difference between acid fast and gram stain. Acid fast staining was developed in ehrlich in 1882 and was later successively modified by ziehl and neelsen. Oocysts in clinical specimens may be difficult to detect without special staining. Application the zn staining technique is used with ordinary brightfield microscopes. Acidfast staining is the primary procedure to detect the presence of mycobacterium mycolic acid, mycobacterium. Detection of acid fast bacilli in saliva using papanicolaou. Use millipore filtered water in the waterbath and staining procedure. The mechanism for acid fastness is not clearly understood, however it is suspected that it is determined by. Ziehlneelsen staining is a type of acidfast stain, first introduced by paul ehrlich.
While acidfast and gram staining are both differential stains, the acidfast stain is much more specific. Franz ziehl 1859 to 1926, a bacteriologist and friedrich neelsen 1854 to 1894 a pathologist. Bisen prakash s microbes in practice, ik international, new delhi, 2014 pp 9155. Learn vocabulary, terms, and more with flashcards, games, and other study tools. More so, it is a physical property of certain bacteria, particularly a bacterias resistance to decolorization by certain acids during staining procedures. Mycobacterium and many nocardia species are called acidfast because during an acidfast staining procedure they retain the primary dye carbol fuchsin despite decolorization with the powerful solvent acidalcohol. The evaluator must understand appropriate methods and ensure they are being followed. The acidfast stain is a differential stain used to identify acidfast organisms such as members of the genus mycobacterium acidfast organisms are characterized by waxlike, nearly impermeable cell walls. Ziehlneelsen staining is a bacteriological stain used to identify acidfast organisms, mainly mycobacteria. Ziehlneelsen zn method of acid fast staining technique is used to stain mycobacterium species including m. An acidfast stain is a laboratory test performed on a sample of.
Nearly all other genera of bacteria are nonacidfast. Such cells are thus termed acidfast in that the cell will hold the stain fast in the presence of the acidic decolorizing agent. Applying carbolfuchsin stain to bacterial smear and heating over water bath for 3 5 minutes. Kappa statistics revealed good agreement between results of both pap staining and ar staining method and culture k 0. Unlike the ziehlneelsen modified acidfast stain, this stain does not require the heating of reagents for. Methods assessed include specimen collection, smear preparation, acid fast stain procedure, reading, and reporting. In the 1890s, friedrich neelsen and franz ziehl modified the stain by adding phenol carbolic acid and basic fuschin. Flood slide with crystal or gentian violet 60 seconds.
Partially acid fast organisms show reddish to purple filaments as opposed to non acid fast organisms, which stain only blue. Acid fast stain free microbiology images from science prof online. Nonacid fast organisms are decolourized by acid fast decolourizer and take up. Acid fast staining is the primary procedure to detect the presence of mycobacterium mycolic acid, mycobacterium. Alternative staining techniques kinyoun or acid fast stain are therefore used that take advantage of the resistance to destaining after lengthier initial staining. Principle cryptosporidium and isospora species have been recognized as causes of severe diarrhea in immunocompromised hosts, but they can also cause diarrhea in the immunocompeten t host. This method is used for those microorganisms which are not staining by simple or gram staining method, particularly the member of genus mycobacterium, are resistant and can only be visualized by acidfast staining. Most bacteria are decolorized by the use of acidalcohol. Detection of acidfast bacilli afb in stained and acidwashed smears examined microscopically may provide the initial bacteriologic evidence of the presence of mycobacteria. Detection of acid fast bacilli in saliva using papanicolaou stain induced fluorescence method versus fluorochrome staining. Acidfast stains detect organisms with waxy cell walls. Acidfast stain definition of acidfast stain by medical.
Phenol appears to combine the pararosaniline dye within the acid fast bacilli. Carefully decolorize with 95% ethanol until thinnest parts of the smear are colorless. Lab 5 acid fast stain questionsanswers flashcards quizlet. An acid fast stain is a laboratory test performed on a sample of. The presence of the acid fast bacteria indicates that there are microorganisms present somewhere in the child that causes tb. Zn acid fast stainskit contains s033, s005 and s022 k005. Staining solutions for acid fast staining sigmaaldrich. Acidfastness is a physical property of certain bacterial and eukaryotic cells, as well as some subcellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. Information from its description page there is shown below. Non acid fast organisms are decolourized by acid fast decolourizer and take up the counter stain. Your doctor can order this test to find out if you have tuberculosis tb or another type of bacterial.
The components of ziehlneelsen stain include primary stain strongconcentrated carbol fuchsin, decolourizer 20%. Ziehlneelsen is a hot method of acid fast staining. Many bacteria are either gram positive or gram negative, but very few are acidfast. Errors done in the decolorizing stage of the acid fast stain could have caused acid fast bacteria to appear non acid fast. Carbolfuchsin solution, microwave 80 power, 45 seconds, allow slides to stand in hot solution for 5 minutes. Ztest revealed that results of the two staining methods, pap staining and ar staining did not differ significantly z 0. Acid fast stainingsummary microbiology lab 11th septravi a patel slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Aug 20, 2011 acid fast staining in tuberculosis slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Unlike the ziehlneelsen modified acid fast stain, this stain does not require the heating of. This file is licensed under the creative commons attributionshare alike 4. The acidfast stain robert koch was the first person to isolate and identify mycobacterium tuberculosis from a patient with tuberculosis. Methods assessed include specimen collection, smear preparation, acidfast stain procedure, reading, and reporting. The waxy mycolic acid containing cell wall of mycobacteia are relatively impermeable to ordinary staining techniques.
1514 66 1573 1262 1160 1453 187 1074 1068 293 146 516 1212 1327 1382 442 751 558 1264 1497 1447 567 574 804 437 121 996 837 565 1309 885 995 383 419 882 1379 744 1223 75