MLT GlobeASCP exam preparation (USA · MLS / MLT) – page 16
1200 practice MCQs for the ASCP medical laboratory exam. Level: Advanced.
The HLA genes in humans make up the:
HLA (human leukocyte antigen) is the name of the human major histocompatibility complex, which strongly influences transplant compatibility.
Corneal transplants are rejected less often than most organ grafts mainly because:
The cornea has no blood vessels and limited lymphatic access, so it is relatively protected from immune attack (immune privilege).
The main purpose of immunosuppressive drugs after organ transplantation is to:
Immunosuppressants such as tacrolimus, cyclosporine and mycophenolate suppress the recipient's immune response so that the graft is not rejected.
A major side effect of long-term immunosuppression after transplantation is an increased risk of:
Suppressing immunity reduces defence against microbes and tumour cells, so transplant recipients have more opportunistic infections and virus-related cancers.
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.
How should urine reagent strips be stored?
Moisture, light, heat and volatile chemicals damage the reagent pads. Strips are kept in their capped container with desiccant and are not refrigerated or frozen.
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.
Thoracentesis is performed to collect which fluid?
Thoracentesis is needle aspiration of the pleural space. Paracentesis collects peritoneal fluid, pericardiocentesis pericardial fluid and arthrocentesis synovial fluid.
Amniotic fluid is collected by which procedure?
Amniocentesis is transabdominal needle aspiration of amniotic fluid from the amniotic sac, used for genetic and fetal testing.
Which substance is used to solidify most bacteriological culture media?
Agar, a seaweed polysaccharide, melts near 100 °C, sets at about 40 °C and is not broken down by most bacteria, so it is the standard solidifying agent.
When is the best time to collect an expectorated sputum sample for bacterial culture?
An early-morning deep-cough sample contains secretions pooled overnight in the lower airways; saliva is not suitable.
Staphylococcus epidermidis is most often a cause of infection in patients with:
S. epidermidis forms biofilms on plastic and metal, so it infects catheters, prosthetic joints and heart valves.
Colonies of Streptococcus pneumoniae dissolve when a few drops of which reagent are added?
Bile salts activate the pneumococcal autolysin, so pneumococci are bile soluble, unlike other alpha-haemolytic streptococci.