Quiz 1 - specimen processing

Polyvinyl alcohol used in the preparation of permanently stained smears of fecal material: a concentrates eggs b dissolves artifacts c serves as an adhesive d enhances stain penetration

c serves as an adhesive

which statement is correct for specimen collection and processing? a. stool samples can contain urine b. stools can be frozen without affecting parasitic structure c. liquid stools are best for detecting ameba and flagellate tophozoites d. unpreserved stools can remain at room temp up to 72 hrs

c. liquid stools are best for detecting ameba and flagellate tophozoites

with a fecal specimen, which one of the following is the most dependeable procedure for the accurate, specific diagnosis of an intestinal amebic infection? a. direct saline wet mount b. direct iodine wet mount c. permanently stained smear d. formalin ethyl

c. permanently stained smear

potential problems using EDTA anticoagulant and holding the blood too long prior to preparation of thick an thin blood films include a. changes in parasite morphology, loss of organisms within several hours, and poor staining b. loos of Schuffner's dots, poor adherence of the blood to the glass slide, and parasites beginning the vector cycle within the tube of blood c. neither A nor B d. all of these options

d. all of these options

a formed stool is received in the lab at 10:30 pm for ova and parasite exam. the night shift tech is certain that the workload will prevent examination of the specimen until 7 am when the next shift arrives. the tech should a. request that a new specimen be collected after 7 am b. hold the specimen at room temperature c. examine a direct prep for trophozoites and freeze the remaining specimen d. preserve the specimen in formalin until it can be examined

d. preserve the specimen in formalin until it can be examined

in a pediatric patient, the recommended clinical specimen for recovery of Enterobius vermicularis is the a. stool specimen b. sigmoidoscopy scrapings c. duodenal aspirates d. series of scotch tape preparations

d. series of scotch tape preparations

which of the following is a key characteristic of the thick blood film? a. the ability to see the parasite within the RBCs b. the ability to identify the parasites to the species level c. the examination of less blood than the thin blood film d. the necessity to lake the RBCs during or prior to staining

d. the necessity to lake the RBCs during or prior to staining

A liquid stool specimen is collected at 10:00 PM and brought to the laboratory for culture and ova and parasite examination. It is refrigerated until 10:10 AM the next day, when the physician requests that the technologist look for amoebic trophozoites (motility). The best course of action would be to: a request a fresh specimen b perform a concentration on the original specimen c perform a trichrome stain on the original specimen d perform a saline wet mount on the original specimen

a request a fresh specimen

which of the following is the preferred anticoagulant for preparing blood smears for diagnosing malaria? a. EDTA b. heparin c. sodium citrate d. sodium fluoride

a. EDTA

oocysts of Cryptosporidium spp. can be detected in stool specimens using a. modified Ziehl-Neelsen acid fast stain b. gram stain c. methenamine silver stain d. trichrome stain

a. modified Ziehl-Neelsen acid fast stain

many parasites have different stages of growth within different hosts. the host where the sexual reproductive stage of the parasites exists is called the a. commensal b. definitive host c. intermediate host d. vector

b. definitive host

Charcot-Leyden crystals in stool may be associated with an immune response and are though to be formed from teh breakdown products of: a. neutrophils b. eosinophils c. monocytes d. lymphocytes

b. eosinophils

the advantage of thick blood smears for malarial parasites is to a. improve staining of the organisms b. improve detection of the organisms c. remove RBC artifacts d. remove platelets

b. improve detection of the organisms