University:
College
Course:
Medical Laboratory Science
Academic year:

2023
Views:

52

Pages:

1
Author:

Carlo M.

ANALYSIS OF URINE AND OTHER BODY FLUIDS LABORATORY INTRO TO FECALYSIS OUTLINE • • Introduction Fecalysis o Materials o Procedure: Macroscopic o Procedure: Occult Blood o Procedure: Microscopic PROCEDURE: OCCULT BLOOD INTRODUCTION • • In the minds of most laboratory personnel, fecal specimen analysis fits into the category of a “necessary evil.” However, as an end product of body metabolism, feces do provide valuable diagnostic information. Routine fecal examination includes macroscopic, microscopic, and chemical analyses for the early detection of gastrointestinal (GI) bleeding, liver and biliary duct disorders, maldigestion/malabsorption syndromes, pancreatic diseases, inflammation, and causes of diarrhea and steatorrhea. • • FECALYSIS PRINCIPLE • Principle: The peroxidase activity of hemoglobin decomposes hydrogen peroxide and the liberated oxygen oxidizes benzidine. Procedure 1. Place a large pinch of guaiac resin in a small test tube. To prevent contamination, use new glasswares whenever possible. 2. Add about 2mL of glacial acetic acid and mix thoroughly. 3. Add a small amount of feces to be tested and mix thoroughly. 4. Add 5 drops of 3% hydrogen peroxide 5. A positive reaction is indicated by green-blue color; reaction is negative when no color change is obtained. It is advisable to run reagent control by adding some actual blood to the tube with the aid of the applicator stick. MATERIALS • • • • • • • • • • PROCEDURE: MICROSCOPIC Stool Specimen Applicator Stick Guaiac resin Glacial Acetic Acid 3% Hydrogen Peroxide Normal Saline Solution Lugol’s (Iodine) Solution Glass Slide Coverslip Microscope PROCEDURE: MACROSCOPIC 1. 2. 3. Bring samples of feces Assemble specimens of the group and number them separately Complete the tabulation. o The gross examination should be directed at finding parasite (whole worms or either fragments) and undigested food and at evaluating the amounts of blood, pus, mucus, and fats present. o Sediments of tapeworm and some adult round worms. Ascaris for example, may at times appear in stool. When necessary, a specimen may be diluted with water, shaken in a close jar, then filtered through the fine sieve or gauze. A hand lens is useful for searching small parasites • • Microscopic examination of feces in clinical microscopy does not focus on the detection of parasites but rather on the detection of the presence of fats, mucus, and cells. The presence of white blood cells in feces could indicate diarrhea caused by pathogenic bacteria while the presence of red blood cells may suggest bleeding. The presence of normal structures need not be reported. Procedure o With the aid of the applicator stick, get a minute amount of the most suspicious portion of the stool emulsified on a drop of saline on a glass slide. o A cover glass is added (Satisfactory smears allow the reading of the printed matter through them). o The preparation is examined under the microscope. This method permits the examination of motile stages in fresh stool. In case of cysts, the addition of drop of dilute Lugol’s solution will help in bringing about details I these structures.