Concentration Techniques.pptx

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Sedimentation



• On light infection, even Kato-Thick smear may not detect it,concentration of the fecal sample is done. One of theseconcentration techniques is Sedimentation. Straining andSedimentation is applied on this technique, Centrifugation mayalso be applied.

• The principle of this technique is that heavy substances(suchas helminthic eggs, larvae, cyst, operculated and schistosomaeggs) tend to go down, and lighter substances (debris) willfloat up.

• In this technique the sediments will be subjected tomicroscopic analysis



• Stool Specimen

• Tongue Depressor

• Gauze pad

• Glass Slide and Cover Slip• Centrifuge Machine

• Centrifuge tube

• 0.5% glycerinated water

• Glass cylinder

• Glass funnel

• Pasteur Pipet• Microscope



• Group 8



406th Medical General Laboratory



• Prepare fecal suspension of 10 parts of water and 1 part

stool specimen.

• Mix thoroughly

• Strain using 2 layers of gauze, collect it in 15 mlcentrifuge tube

• Add NSS until tube is ¾ full (0.5% glycerinated water)

• Centrifuge for 2 min. @ 1500rpm

• Decant the supernatant• Repeat the process, up to 3 times



• Add 7ml of 10% Formalin

• Stand for 5 to 10 min

• Add 3ml of formalized specimen

• Mix thoroughly• Centrifuge for 2 min @ 1500 rpm

• Ether, superficial debris and formalin are decant

• Pipette a drop of the sediment to the glass slide

• Add a drop of NSS

• Examine under microscope





• Potassium Hydroxide Concentration Method for

Cyclospora (Berlin et al., 1994)

• 10% KOH

• Stand for 5 min

• Saline

• Filter with 4 layers of gauze

• Centrifuge

• Decant

• Saline• Centrifuge

• Decant

• Examine sediment



• Ritchie Concentration Method

• - same as Formalin-Ether Concentration Technique only

that it uses Ethyl Acetate instead of ether

• Sedimentation in water

• Not effective as a concentration Technique



• Acid-Ether Sedimentation

• Dissolves mucus and other various substance

• Unsatisfactory for the diagnosis of protozoa

• Useful for detection of schistosome and other trematode eggs

• 15% HCl

• Acid

• Strain

• Centrifuge• Acid

• Ether

• Centrifuge

• Study Sediment



• Adaptation of Ritchie's Method for Parasites

Diagnosing with Minimization of ChemicalProducts

• Régis Silva Anécimo, Karina A. A. Tonani, Brisa Maria Fregonesi, Ana Paula Mariano,Marinês D. B. Ferrassino, Tânia M. B. Trevilato, Roberta Braga Rodrigues, and Susana I.Segura-Muñoz Central Laboratory of Clinical Pathology, University Hospital, University of São Paulo at Ribeirão Preto Medical School, 14040-902 Ribeirão Preto, SP, BrazilLaboratory of Ecotoxicology and Environmental Parasitology, University of São Paulo at

Ribeirão Preto College of Nursing, Avenida Bandeirantes 3900, Campus Universitário,14040-902 Ribeirão Preto, SP, Brazil Microtechnics/Metal Sector, University of São Paulo atRibeirão Preto Medical School Hospital das Clínicas, 14040-902 Ribeirão Preto, SP, Brazil

• Received 31 May 2012; Accepted 8 July 2012

• Academic Editor: Oladele O. Kale

• Copyright © 2012 Régis Silva Anécimo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, andreproduction in any medium, provided the original work is properly cited.



• Abstract

• Latin America, Africa, and Asia present wide dissemination and high prevalencerates of waterborne parasitic diseases, which is a strong indicative of the fragility

of public sanitation systems. In this context, parasitological analyses representextremely relevant instruments. Several parasite diagnosis methods exist,among which Ritchie’s method (1948) stands out. This method usesformaldehyde and ether, two reagents of toxicological importance that can causedamages to environmental and occupational health. The present study aimed tocompare Ritchie’s method modified by Régis Anécimo, without use of solvents,with the traditional Ritchie’s method, routinely used for helminth and protozoadiagnosing in Brazil. Some changes were introduced in the modified method,

such as controlled increase of water temperature used after stool dilution andsubstitution of formaldehyde and ether by a neutral detergent before materialcentrifugation for observation of parasites. In examined samples by bothmethods, multiple infections were commonly observed; the modified methodpresented a similar sensitivity to identify the parasites. The development of analytic diagnosis methods that minimize the use of chemical products like ether and formaldehyde represents an important tool to prevent occupational diseasesamong exposed professionals, as well as to preserve environmental quality

through the use of clean techniques.



• Update: http://www.hindawi.com/journals/ipid/2012/409757 (Last

Accessed on January 16, 2013)

• Beaver, Jung and Cupp, “ Clinical Parasitology 9th ed.”, 1984

• John and Petri, “Markell and Voge’s Medical Parasitology 9th ed.” 2010 • Brown and Neva, “Clinical Parasitology”, 1983

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Concentration Techniques.pptx