MLT GlobeASCP exam preparation (USA · MLS / MLT) – page 3
1200 practice MCQs for the ASCP medical laboratory exam. Level: Advanced.
A red-top tube for glucose was left unspun at room temperature for 4 hours before testing. The result will most likely be:
Cells continue to use glucose; the loss is about 5–7% per hour at room temperature. Serum must be separated quickly or a glycolytic inhibitor used.
Whipple triad, used to confirm true hypoglycemia, consists of:
Whipple triad links symptoms to a documented low glucose and their relief after glucose is raised. Insulin and C-peptide are used later to find the cause.
A blood sample for electrolytes was stored refrigerated overnight before separation. Which result is expected?
Cold inhibits Na+/K+-ATPase, so potassium leaks out of cells into plasma. Glucose falls with storage, and phosphate tends to rise with cell leakage.
The main form in which total CO2 exists in serum, and is measured as 'bicarbonate' on chemistry analysers, is:
About 90–95% of total CO2 in plasma is bicarbonate ion; dissolved CO2 and carbonic acid make up a small part. Tubes left uncapped lose CO2, giving falsely low results.
Anti-Müllerian hormone (AMH) is mainly used to assess:
AMH is made by granulosa cells of small growing follicles and reflects the remaining follicle pool. It is used in fertility assessment and falls towards menopause.
Which creatine kinase isoenzyme makes up almost all of the CK activity in normal skeletal muscle?
Skeletal muscle CK is nearly all CK-MM, which is also the main form in normal serum. CK-MB is enriched in myocardium, and CK-BB in brain, bowel and prostate.
Which aminotransferase is more specific for liver injury?
ALT is found mainly in hepatocyte cytoplasm, while AST is also present in heart, skeletal muscle and red cells. Therefore ALT is more liver-specific.
Which lipoprotein has the highest density?
HDL has the most protein and least triglyceride, so it is the densest. Chylomicrons are the largest and least dense.
In the enzymatic cholesterol method, the role of cholesterol esterase is to:
About 70% of plasma cholesterol is esterified, so esterase frees it before cholesterol oxidase acts. The oxidase, not the esterase, produces hydrogen peroxide.
Total cholesterol is 6.2 mmol/L, HDL 1.4 mmol/L and triglycerides 1.8 mmol/L. What is the non-HDL cholesterol?
Non-HDL cholesterol = total cholesterol - HDL = 6.2 - 1.4 = 4.8 mmol/L. Triglycerides are not used; also subtracting the VLDL term (TG/2.2 = 0.8) gives the Friedewald LDL of about 4.0 mmol/L, not non-HDL cholesterol.
A healthy, breastfed 2-week-old has persistent mild unconjugated hyperbilirubinemia, normal stools and no hemolysis. The most likely cause is:
Breast milk jaundice begins after the first week and can last several weeks, with unconjugated bilirubin in a thriving baby. Biliary atresia gives conjugated bilirubin and pale stools.
A patient with long-standing cirrhosis has a rising serum alpha-fetoprotein and a new liver mass. The most likely diagnosis is:
AFP is used with imaging to detect hepatocellular carcinoma in cirrhosis. Benign lesions such as abscess or hemangioma do not typically raise AFP.
A woman with systemic lupus erythematosus has a broad, diffuse increase across the entire gamma region on electrophoresis. This is best described as:
A wide, smooth gamma increase reflects many plasma-cell clones making different immunoglobulins, typical of chronic inflammation, autoimmune disease or chronic infection. A monoclonal protein gives a narrow, sharp band.
The upper reference limit for total protein excretion in urine of a healthy adult is about:
Healthy adults excrete less than about 150 mg of protein per day, much of it uromodulin and small amounts of albumin. Levels near 1500 mg/day are clearly pathologic.
Which condition is best known for markedly raised serum uric acid due to rapid cell breakdown?
Tumor lysis releases nucleic acids, whose purines are degraded to uric acid, which may crystallise in the tubules. Fanconi syndrome and Wilson disease often cause low uric acid through renal loss.
A patient has eGFR 38 mL/min/1.73 m² that has been stable for 6 months. Which KDIGO GFR category is this?
KDIGO GFR categories: G3a 45–59, G3b 30–44, G4 15–29 mL/min/1.73 m². A value of 38 is G3b; persistence over 3 months satisfies the chronicity criterion.
Tacrolimus and cyclosporine are measured in which specimen?
These drugs are concentrated in red cells, and plasma levels depend on temperature and hematocrit. EDTA whole blood gives the most reliable results.
Which tumor marker is used mainly to monitor metastatic breast cancer?
CA 15-3 (a MUC1 antigen) is used to follow response and recurrence of breast cancer. It is not sensitive enough for early detection.
The main clinical use of most serum tumor markers is to:
Most markers lack the sensitivity and specificity for population screening. Serial measurements in a known patient are most useful for follow-up.
Which pattern fits iron deficiency anemia?
In iron deficiency, the liver makes more transferrin (high TIBC) while iron and stores (ferritin) fall. Low iron with low TIBC and high ferritin is typical of anemia of chronic disease.