TheoryMedical Lab Tech ASCP
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30 free Medical Lab Tech ASCP questions
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Hematology
Which red cell index is calculated as (hemoglobin / hematocrit) x 100 and reflects the average concentration of hemoglobin in a given volume of packed red cells?
Correct — B. MCHC = (Hgb/Hct) x 100, reported in g/dL; it describes hemoglobin concentration per unit of packed cell volume, unlike MCV (size) or MCH (content per cell). -
Hematology
A patient has a hemoglobin of 12 g/dL and a hematocrit of 36%. What is the MCHC?
Correct — C. MCHC = (Hgb/Hct) x 100 = (12/36) x 100 = 33.3 g/dL, within the normal reference range of roughly 32-36 g/dL. -
Hematology
A red cell count of 4.0 x 10^12/L and a hematocrit of 36% give which MCV?
Correct — A. MCV = (Hct% x 10) / RBC(x10^12/L) = (36 x 10)/4.0 = 90 fL, a normocytic value within the 80-100 fL reference interval. -
Hematology
Microcytic, hypochromic red cells with a low MCV and elevated RDW most classically suggest which condition?
Correct — B. Iron deficiency produces small (low MCV), pale (low MCHC) cells with increased size variation (high RDW); megaloblastic anemias from folate/B12 deficiency are macrocytic instead. -
Hematology
Which leukocyte is the primary mediator of acute bacterial infection and is the most numerous WBC in normal adult peripheral blood?
Correct — C. Neutrophils (segmented forms) normally make up 50-70% of circulating leukocytes and are first responders to acute bacterial infection through phagocytosis. -
Hematology
Increased eosinophils in the peripheral blood are most characteristically associated with which of the following?
Correct — D. Eosinophilia classically accompanies parasitic (helminth) infections and allergic/hypersensitivity states; bacterial infection drives neutrophilia instead. -
Hematology
Which cell fragment is chiefly responsible for primary hemostasis through adhesion and aggregation at sites of vascular injury?
Correct — A. Platelets (thrombocytes) adhere to exposed subendothelial collagen via von Willebrand factor and aggregate to form the primary platelet plug. -
Hematology
Platelet clumping caused by EDTA-dependent agglutinins typically produces what spurious result on an automated analyzer?
Correct — B. EDTA-induced clumps are counted as single large particles or excluded, lowering the reported count; redrawing in sodium citrate and correcting for dilution resolves the pseudothrombocytopenia. -
Hematology
A reticulocyte count is best used to assess which of the following?
Correct — C. Reticulocytes are young anucleate red cells containing residual RNA; an elevated count indicates active marrow red-cell production, as in hemolysis or response to blood loss. -
Hematology
Residual ribosomal RNA in reticulocytes is demonstrated with which type of stain?
Correct — A. Reticulocyte RNA is precipitated only by supravital stains (new methylene blue or brilliant cresyl blue) applied to living cells; Wright stain does not reliably show the reticulum. -
Hematology
Sickle cell anemia results from a single amino acid substitution in which globin chain?
Correct — B. Hemoglobin S arises from substitution of valine for glutamic acid at the sixth position of the beta-globin chain, causing polymerization and sickling under low-oxygen conditions. -
Hematology
On hemoglobin electrophoresis at alkaline pH, which hemoglobin migrates the fastest toward the anode?
Correct — C. At alkaline pH (8.6), Hgb A is the most negatively charged of the common variants and migrates fastest toward the anode, ahead of F, S, and C. -
Hematology
Auer rods seen in the cytoplasm of blasts are most specific for which lineage of acute leukemia?
Correct — A. Auer rods are crystallized azurophilic granules found only in myeloid blasts, supporting a diagnosis of AML rather than ALL. -
Hematology
A markedly elevated WBC count with the full spectrum of granulocyte maturation and a very low leukocyte alkaline phosphatase score suggests which disorder?
Correct — D. CML shows a left-shifted granulocytic series with a characteristically LOW LAP score, whereas a benign leukemoid reaction shows a HIGH LAP score. -
Hematology
The erythrocyte sedimentation rate (ESR) is primarily a nonspecific indicator of which process?
Correct — B. ESR rises with increased plasma fibrinogen and globulins that promote rouleaux and faster settling; it is a nonspecific marker of inflammation, not a diagnostic test. -
Hematology
The prothrombin time (PT) primarily evaluates which coagulation pathway?
Correct — C. PT measures factors VII (extrinsic) plus X, V, II, and fibrinogen (common pathway); the aPTT instead evaluates the intrinsic and common pathways. -
Hematology
The activated partial thromboplastin time (aPTT) is the test of choice to monitor therapy with which anticoagulant?
Correct — A. Unfractionated heparin potentiates antithrombin and prolongs the aPTT, which is the standard monitoring assay; warfarin is monitored by PT/INR. -
Hematology
The INR was developed primarily to standardize the reporting of which test across different reagent lots and laboratories?
Correct — B. The International Normalized Ratio normalizes PT results using the ISI of the thromboplastin reagent so warfarin dosing is comparable regardless of reagent source. -
Hematology
A correctly filled 3.2% sodium citrate (blue-top) coagulation tube uses what ratio of anticoagulant to whole blood?
Correct — C. The standard citrate ratio is 1:9 (one volume anticoagulant to nine volumes blood); underfilling raises the effective citrate concentration and falsely prolongs clotting times. -
Hematology
Using a Neubauer hemocytometer, cells counted in the four large corner squares total 100, with a 1:20 dilution (depth 0.1 mm, area 4 mm^2). What is the approximate WBC count per microliter?
Correct — C. Count/uL = (cells x dilution) / (area x depth) = (100 x 20) / (4 x 0.1) = 2000 / 0.4 = 5,000/uL. -
Hematology
Howell-Jolly bodies on a peripheral smear are nuclear remnants most commonly seen after which event?
Correct — D. The spleen normally pits these DNA remnants from red cells, so Howell-Jolly bodies appear after splenectomy or in functional asplenia. -
Hematology
Target cells (codocytes) are classically increased in all of the following EXCEPT:
Correct — A. Hereditary spherocytosis produces spherocytes with no central pallor, the opposite of target cells; targets occur in liver disease, thalassemia, and Hgb C. -
Hematology
Hypersegmented neutrophils and oval macrocytes on a smear, with an elevated MCV, point toward which deficiency?
Correct — B. Megaloblastic anemia from B12 or folate deficiency impairs DNA synthesis, producing macro-ovalocytes and neutrophils with six or more nuclear lobes. -
Hematology
Reactive (atypical) lymphocytes with abundant basophilic cytoplasm are most characteristic of which infection?
Correct — C. Epstein-Barr virus infection classically produces large reactive lymphocytes (Downey cells) and a positive heterophile antibody test in infectious mononucleosis. -
Hematology
A Prussian blue stain of a bone marrow aspirate is used primarily to evaluate which of the following?
Correct — D. Prussian blue (Perls) stain reveals hemosiderin iron stores and identifies ring sideroblasts, iron-laden mitochondria encircling the nucleus. -
Hematology
When 25 nucleated red cells are seen per 100 WBCs and the automated WBC count is 12.0 x 10^9/L, what is the corrected WBC count?
Correct — B. Corrected WBC = uncorrected x 100/(100 + NRBC) = 12.0 x 100/125 = 9.6 x 10^9/L; nucleated red cells are otherwise miscounted as leukocytes. -
Hematology
Von Willebrand factor serves which two principal functions in hemostasis?
Correct — A. VWF bridges platelets to subendothelial collagen and stabilizes circulating factor VIII; its deficiency causes von Willebrand disease, the most common inherited bleeding disorder. -
Hematology
Which anticoagulant is the standard for routine CBC and morphology specimens?
Correct — C. EDTA (lavender top) chelates calcium and best preserves cellular morphology and counts; citrate is for coagulation and heparin for chemistry/special tests. -
Hematology
Disseminated intravascular coagulation is typically associated with which laboratory pattern?
Correct — D. DIC consumes platelets and clotting factors while generating fibrin degradation products, giving long PT/aPTT, low platelets, low fibrinogen, and elevated D-dimer. -
Hematology
Thick and thin blood films for malaria are best used in which way?
Correct — A. The thick film concentrates parasites for sensitive detection, while the thin film preserves red cell and parasite morphology needed to speciate Plasmodium.
Medical Lab Tech ASCP sample questions
Tap any question below to reveal the answer and a plain-English explanation.
Hematology An elevated red cell mass with a low serum erythropoietin level is most consistent with which condition?
A. High-altitude adaptation
B. Polycythemia vera ✓
C. Chronic hypoxic lung disease
D. Renal tumor secreting EPO
Correct — B. Polycythemia vera is a clonal myeloproliferative neoplasm (often JAK2-mutated) that suppresses EPO, unlike secondary polycythemias driven by elevated EPO.
Clinical Chemistry Which gray-top additive both inhibits glycolysis and acts as an anticoagulant to preserve glucose in a specimen?
A. EDTA only
B. Sodium fluoride with potassium oxalate ✓
C. Lithium heparin
D. Sodium citrate
Correct — B. Sodium fluoride inhibits enolase to stop glycolysis, while potassium oxalate anticoagulates; together they preserve glucose that would otherwise drop with time at room temperature.
Microbiology In the Gram stain, which reagent acts as the decolorizer that differentiates gram-positive from gram-negative cells?
A. Crystal violet
B. Acetone-alcohol ✓
C. Safranin
D. Gram's iodine
Correct — B. The acetone-alcohol decolorizer washes the crystal violet-iodine complex out of thin-walled gram-negative cells while thick peptidoglycan retains it in gram-positive cells.
Immunohematology / Blood Bank An individual with blood group O has which antibodies in their plasma?
A. No ABO antibodies
B. Anti-A only
C. Anti-A and anti-B ✓
D. Anti-B only
Correct — C. Group O individuals lack A and B antigens and naturally produce both anti-A and anti-B (predominantly IgM), making O the universal red cell donor.
Immunology & Serology Which immunoglobulin class is the most abundant in serum and the only one that crosses the placenta?
A. IgM
B. IgG ✓
C. IgA
D. IgE
Correct — B. IgG is the predominant serum antibody and the only class actively transported across the placenta, providing passive immunity to the newborn.
Urinalysis & Body Fluids Which urine specimen is preferred for routine urinalysis because it is the most concentrated?
A. Random midday specimen
B. First morning specimen ✓
C. 24-hour collection
D. Catheterized specimen
Correct — B. The first morning specimen is the most concentrated and acidic, improving detection of formed elements and substances like protein and nitrite.
Lab Operations & QC A Levey-Jennings chart is used primarily to do which of the following?
A. Calibrate pipettes
B. Plot daily control values to monitor analytical performance over time ✓
C. Record patient demographics
D. Track reagent inventory
Correct — B. The Levey-Jennings chart plots control results against the mean and standard deviation limits over time, allowing visual detection of trends, shifts, and out-of-control events.
Lab Safety Standard precautions are based on which underlying principle?
A. Only known infectious patients are hazardous
B. All blood and body fluids are treated as potentially infectious ✓
C. Only blood is infectious
D. Gloves alone provide complete protection
Correct — B. Standard precautions assume that every patient's blood and body fluids may carry bloodborne pathogens, so protective measures are applied universally regardless of known diagnosis.
About the Medical Lab Tech ASCP test
The Medical Lab Tech ASCP measures the Nursing/Medical knowledge you'll actually rely on — tested the way the real exam asks it, not with trick questions. Practising real Medical Lab Tech ASCP-style questions, then sitting a full timed mock exam, is the fastest way to walk in knowing you'll pass.
You will be tested on
- Safe and effective care environment
- Health promotion and maintenance
- Psychosocial and physiological integrity
- Pharmacology, infection control and patient safety
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Topics in this question bank
Safe and effective care environment
Health promotion and maintenance
Psychosocial and physiological integrity
Pharmacology, infection control and patient safety
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