MLT GlobeDOH exam preparation (Abu Dhabi) – page 17
700 practice MCQs for the DOH medical laboratory exam. Level: Basic to intermediate.
A microscope with a 10× eyepiece and a 100× oil-immersion objective gives a total magnification of:
Total magnification is eyepiece × objective: 10 × 100 = 1000×.
Daily quality control results for an analyzer are plotted over time on a:
A Levey-Jennings chart plots control values against the mean and SD limits over time, helping to spot shifts and trends. A Price-Jones curve shows red cell diameters.
Reverse (serum) grouping is important in ABO typing mainly because it:
Forward and reverse grouping must agree. The reverse group confirms the forward result and helps to reveal errors and discrepancies.
In Wiener notation, R2 corresponds to which Fisher-Race haplotype?
R2 = DcE. R1 = DCe, R0 = Dce and r = dce.
Anti-K is most often of which immunoglobulin class?
Anti-K is usually an IgG immune antibody detected at the AHG phase. It can cause hemolytic transfusion reactions and HDFN.
The antigens Jka and Jkb belong to which blood group system?
Jka and Jkb are the Kidd antigens. Kidd antibodies are known for causing delayed hemolytic transfusion reactions.
Fresh frozen plasma is used because it contains:
Freezing plasma soon after collection keeps all clotting factors, including the unstable factors V and VIII.
Where should red cell units be stored before transfusion?
Red cells need a dedicated blood bank refrigerator with continuous temperature monitoring and alarms. Domestic refrigerators are not controlled, and freezing without glycerol lyses red cells.
Apheresis is a collection method in which:
An apheresis machine draws blood, separates out the chosen component (such as platelets or plasma) and returns the rest to the donor.
After a suspected transfusion reaction, which items should be sent to the blood bank?
The bag and set allow rechecking and culture of the unit, and the post-transfusion sample is used for clerical checks, hemolysis check, DAT and repeat grouping.
The most frequent form of HDFN is:
ABO HDFN, mainly in group A or B babies of group O mothers, is the most common form but is usually mild.
The reagent strip protein pad is most sensitive to which protein?
The protein-error-of-indicators pad reacts mainly with albumin and is much less sensitive to globulins and free light chains (Bence Jones protein).
A positive nitrite test on a reagent strip indicates:
Many Gram-negative urinary pathogens, especially Enterobacterales such as E. coli, reduce dietary nitrate to nitrite, so a positive nitrite suggests bacteriuria.
In a healthy adult, the reagent strip glucose result is normally:
Filtered glucose is almost completely reabsorbed by the proximal tubule, so normal urine gives a negative glucose pad.
Urinary casts are formed mainly in the:
Casts are moulds of the tubular lumen formed when uromodulin gels in the distal tubules and collecting ducts, so they come only from the kidney.
In a normal urine sediment, red blood cells are usually seen at about:
A few red cells (roughly 0–2 or 0–3 per HPF) can be normal. Higher numbers indicate hematuria and need investigation.
In a normal urine sediment, white blood cells are usually seen at about:
Up to about 5 white cells per HPF is generally regarded as normal; higher counts indicate pyuria, often due to infection or inflammation.
Which traditional stain is used on CSF to show the capsule of Cryptococcus neoformans?
India ink provides a dark background so the unstained polysaccharide capsule of Cryptococcus appears as a clear halo. Cryptococcal antigen testing is more sensitive.
A cloudy (turbid) CSF is most often caused by:
Turbidity usually results from many white cells (as in bacterial meningitis), and also from bacteria, red cells or high protein.
Gram-negative diplococci seen in the CSF of a young adult with meningitis and a rash are most likely:
Neisseria meningitidis appears as Gram-negative kidney-shaped diplococci and often causes a petechial or purpuric rash. S. pneumoniae is a Gram-positive diplococcus.