TOOL CONCENTRATION TECHNIQUES​ CLIPAR LAB - MIDTERM REAL

Stool Concentration Techniques

Methods used to increase recovery of parasites in stool; includes sedimentation and flotation

Sedimentation techniques

Methods that concentrate parasites by allowing them to settle at the bottom

Flotation techniques

Methods that concentrate parasites by floating them using high specific gravity solutions

Formalin Ether Concentration Technique (FECT)

Sedimentation method using formalin and ether to recover helminth eggs, larvae, and protozoan cysts

Acid Ether Concentration Technique (AECT)

Sedimentation method using HCl and ether; best for Trichuris, Capillaria, and trematode eggs

Gravity Sedimentation

Simplest sedimentation method; uses large fecal sample and no centrifuge

Centrifugal Sedimentation

Sedimentation method using centrifugation for faster parasite recovery

MIF Sedimentation

Merthiolate-Iodine-Formaldehyde method; concentrates all stages including trophozoites

Modified Zinc Sulfate Concentration

Flotation method using zinc sulfate solution (SG 1.18-1.20)

Brine Flotation Technique

Flotation method using salt solution; good for hookworm screening

Sheather's Sugar Flotation Technique

Flotation method using sugar solution; best for coccidian oocysts

Gravity Sedimentation characteristics

Simplest, efficient for eggs/larvae/cysts, useful for Schistosome eggs, ideal in remote areas

Centrifugal Sedimentation characteristics

Faster than gravity, reveals living organisms, uses large fecal sample, no expensive reagents

Formalin Ether Sedimentation characteristics

Preserves morphology, dissolves fats, allows long storage, uses formalin-preserved stool

MIF Sedimentation characteristics

Rapid, simple, high positivity rate, concentrates all parasite stages within one week

Acid Ether Sedimentation characteristics

Dissolves albumin and fats, best for animal stool, destroys protozoan cysts, may lose parasites in debris

Brine Flotation characteristics

Simple, good for helminth eggs except operculated and Schistosomes, distorts protozoan cysts

Zinc Sulfate Flotation characteristics

Used for surveys, detects protozoan cysts and roundworm eggs, may distort cysts if SG is high

Sheather's Sugar Flotation characteristics

Best for coccidian oocysts, uses sugar solution with phenol, good visualization under microscope

Schistosoma japonicum location

Found in the small intestine

Schistosoma haematobium location

Found in the bladder

Schistosoma mansoni location

Found in the large intestine

Acid Ether reagents

40% HCl (dissolves albumin) and ether (dissolves fats)

Zinc Sulfate reagent

33% zinc sulfate solution with specific gravity of 1.18-1.20

Sheather's Sugar reagent

Boiled sugar solution preserved with phenol

Does not float in Zinc Sulfate

Fertile Ascaris eggs

Does not float in Zinc Sulfate

Infertile Trichuris eggs

Does not float in Zinc Sulfate

Most trematode eggs

Does not float in Zinc Sulfate

Operculated tapeworm eggs

Does not float in Zinc Sulfate

Other heavy helminth eggs and larvae

Brine Flotation limitation

Distorts protozoan cysts and shrinks larvae and Schistosomes

Acid Ether limitation

Destroys protozoan cysts and may trap parasites in debris

Zinc Sulfate limitation

High specific gravity may distort protozoan cysts

Sheather's Sugar advantage

Best recovery for Cryptosporidium, Isospora, and Cyclospora oocysts