MLT GlobeSCFHS exam preparation (Saudi Arabia) – page 14
749 practice MCQs for the SCFHS medical laboratory exam. Level: Intermediate.
The first stage of hemagglutination, in which antibody binds to red cell antigen, is called:
Agglutination has two stages: sensitization (antibody attaches to antigen) and lattice formation (antibody bridges cells to form visible clumps).
A crossmatch is considered compatible when:
Compatible means no agglutination and no hemolysis at any phase tested. Hemolysis counts as a positive (incompatible) reaction.
Donor red cells for crossmatching are usually taken from:
Segments attached to the bag contain the same donor blood and can be removed without opening the unit.
During a transfusion, the patient must be watched most closely during the first:
Severe reactions such as acute hemolysis and anaphylaxis usually start early, so vital signs are checked and the patient observed closely in the first 15 minutes.
Blood components such as red cells, plasma and platelets are separated from whole blood mainly by:
Centrifuging whole blood separates red cells, platelets and plasma into layers according to their density and size.
The main purpose of a red cell transfusion is to:
Red cells are given to improve oxygen delivery in symptomatic anemia or blood loss. Plasma, platelets and albumin are used for the other needs.
Bleeding in a patient with severe hemophilia A is best treated with:
Hemophilia A is factor VIII deficiency, so bleeding is treated with factor VIII concentrate (recombinant or plasma-derived).
In CPD anticoagulant-preservative, sodium phosphate acts mainly as a:
Phosphate buffers the acid produced during storage, which helps preserve 2,3-DPG. Citrate binds calcium and dextrose supplies energy.
After donating whole blood, a donor should be advised to:
Extra fluids help restore blood volume. Avoiding heavy exertion lowers the risk of fainting and of bleeding at the needle site.
The donor health questionnaire is mainly used to:
The questionnaire finds donors who could be harmed by donating or whose blood could harm a recipient, for example through recent risk behavior or illness.
Systematic monitoring and reporting of adverse events linked to transfusion is called:
Hemovigilance covers the whole transfusion chain, from donor to recipient, to find and prevent adverse events. Look-back is tracing earlier recipients of a donor later found infected.
Hemolytic disease of the fetus and newborn is caused by:
In HDFN, maternal IgG against a fetal red cell antigen (such as D) crosses the placenta and coats fetal red cells, which are then destroyed.
HDFN was historically called 'erythroblastosis fetalis' because:
The anemic fetus releases large numbers of erythroblasts (nucleated red cells) into its circulation.
Before a fasting plasma glucose test, an adult should have had no caloric intake for at least how long?
ADA defines fasting as no caloric intake for at least 8 hours. Shorter fasts can give falsely high results, and a 24-hour fast is not required.
Lactose, the sugar in milk, is made of which two monosaccharides?
Lactose is a disaccharide of glucose and galactose. Glucose plus fructose forms sucrose, and two glucose units form maltose.
Which specimen is used to measure HbA1c?
HbA1c is measured in red cells, so anticoagulated whole blood (usually EDTA) is used. Serum and separated plasma contain no red cells.
The approximate reference interval for total serum protein in adults is:
Adult total serum protein is roughly 6–8 g/dL (60–80 g/L), with exact limits varying slightly between laboratories. Albumin alone is about 3.5–5.0 g/dL.
Bence Jones protein in urine consists of:
Bence Jones proteins are free monoclonal kappa or lambda light chains, small enough to pass the glomerulus; they are typical of multiple myeloma.
Enzymes are biological catalysts made mainly of:
Almost all enzymes are proteins. They speed reactions without being consumed. (A few RNA catalysts exist, but they are exceptions.)
The CK-MB isoenzyme is found in its highest proportion in which tissue?
Cardiac muscle contains the highest proportion of CK-MB (roughly 20–30% of its CK), which is why CK-MB was used as a marker of myocardial infarction.