سأعود لنشر أحدث الاسئلة المتاحة لامتحان الهيئة السعودية للتخصصات الطبية مختبرات 2026 ولكن يجب الإشارة لاهم التعديلات علي الامتحانات وقواعدها:
The current SCFHS SLLE applicant guide describes a 200-item, four-option, single-best-answer examination divided into two 100-question parts, with 120 minutes per part and a scheduled 30-minute break. It evaluates both knowledge and scenario-based interpretation, decision making, calculation, and laboratory-procedure competencies.
Total questions: 200
Format: Four options per question: A, B, C, D
Instruction: Select the one best answer
Part I: Questions 1–100; recommended time 120 minutes
Break: 30 minutes
Part II: Questions 101–200; recommended time 120 minutes
Candidate-facing sections: Questions only; answers are provided separately after Question 200.
BLUEPRINT
The following practice blueprint follows the public SLLE domain ranges. SCFHS notes that actual blueprint distributions may vary within stated tolerances; this simulation uses a balanced 200-question allocation.
| Domain | Target % | Practice count | Major topics represented |
|---|---|---|---|
| Blood Bank / Immunohematology | 15–20% | 34 | ABO/Rh, antibody testing, transfusion, HDFN, reactions, components |
| Urinalysis & Other Body Fluids | 5–10% | 14 | Urinalysis, sediment, CSF, synovial, serous fluid, semen, feces |
| Clinical Chemistry | 15–20% | 34 | Acid-base, electrolytes, renal/liver testing, endocrinology, toxicology |
| Hematology & Hemostasis | 15–20% | 34 | CBC, morphology, hemoglobinopathy, coagulation, flow cytometry |
| Immunology & Serology | 5–10% | 14 | Autoimmunity, immune response, viral and infectious serology |
| Histo- & Cytotechniques | 5–10% | 12 | Fixation, processing, staining, frozen sections, cytology |
| Microbiology | 15–20% | 34 | Bacteriology, mycology, virology, parasitology, AST |
| Laboratory Operations | 5–10% | 12 | QC, validation, safety, calculations, information systems |
| Patient Safety & Professionalism | 5–10% | 12 | Identification, critical values, confidentiality, ethics, communication |
| Total | 100% | 200 | — |
PART I
Questions 1–100
Recommended time: 120 minutes
1
A patient’s RBCs agglutinate with anti-A and anti-D reagents but not with anti-B reagent. The serum agglutinates B reagent cells but not A1 cells. What is the most likely ABO/Rh type?
A. A positive
B. A negative
C. AB positive
D. O positive
Correct answer: A
Why: Anti-A and anti-D reactivity identifies A-positive RBCs. Serum reaction with B cells confirms anti-B, which is expected in group A individuals.
Why the other options are wrong:
B — An A-negative person would not react with anti-D.
C — AB-positive serum should generally lack anti-A and anti-B.
D — Group O RBCs do not react with anti-A.
2
Which anticoagulant is most appropriate for routine complete blood count testing?
A. Sodium citrate
B. EDTA
C. Heparin
D. Sodium fluoride
Correct answer: B
Why: EDTA chelates calcium and preserves cellular morphology, making it appropriate for routine CBC testing.
Why the other options are wrong:
A — Sodium citrate is primarily used for coagulation testing.
C — Heparin is mainly used for plasma chemistry and blood gases.
D — Sodium fluoride inhibits glycolysis for glucose testing.
3
A fresh urine specimen is strongly positive for nitrite and leukocyte esterase. Which finding is most consistent with these results?
A. Bacterial urinary tract infection
B. Nephrotic syndrome
C. Diabetic ketoacidosis
D. Hepatocellular jaundice
Correct answer: A
Why: Nitrite suggests nitrate-reducing bacteria, and leukocyte esterase indicates neutrophils. Together they support bacterial UTI.
Why the other options are wrong:
B — Nephrotic syndrome is characterized by significant proteinuria and lipiduria.
C — Ketoacidosis produces ketones and often glucose.
D — Hepatocellular jaundice may cause bilirubinuria and increased urobilinogen.
4
Which enzyme is most specific for acute pancreatitis when measured in serum?
A. Alkaline phosphatase
B. Creatine kinase
C. Lipase
D. Lactate dehydrogenase
Correct answer: C
Why: Serum lipase is more pancreas-specific and usually remains elevated longer than amylase in acute pancreatitis.
Why the other options are wrong:
A — ALP is associated with cholestasis and bone disease.
B — CK reflects muscle injury.
D — LD is nonspecific.
5
A Gram-positive coccus produces catalase and coagulase. Which organism is most likely?
A. Staphylococcus aureus
B. Streptococcus pyogenes
C. Enterococcus faecalis
D. Streptococcus pneumoniae
Correct answer: A
Why: Staphylococcus aureus is Gram-positive, catalase-positive, and coagulase-positive.
Why the other options are wrong:
B — S. pyogenes is catalase-negative.
C — Enterococcus is catalase-negative.
D — S. pneumoniae is catalase-negative and alpha-hemolytic.
6
Which blood component is most appropriate for a patient with active bleeding and a critically low fibrinogen concentration?
A. Packed red blood cells
B. Platelet concentrate
C. Fresh frozen plasma
D. Cryoprecipitate
Correct answer: D
Why: Cryoprecipitate is concentrated in fibrinogen and is used when fibrinogen replacement is required.
Why the other options are wrong:
A — RBCs restore oxygen-carrying capacity.
B — Platelets treat thrombocytopenia or platelet dysfunction.
C — FFP provides multiple clotting factors but is less concentrated for fibrinogen replacement.
7
The presence of Auer rods in blasts is most strongly associated with:
A. Acute lymphoblastic leukemia
B. Acute myeloid leukemia
C. Chronic lymphocytic leukemia
D. Hairy cell leukemia
Correct answer: B
Why: Auer rods are azurophilic needle-like inclusions in myeloid blasts and strongly support AML.
Why the other options are wrong:
A — ALL blasts do not contain Auer rods.
C — CLL shows mature lymphocytosis and smudge cells.
D — Hairy cell leukemia shows lymphocytes with cytoplasmic projections.
8
A urine specific gravity of 1.035 is most likely caused by:
A. Marked dilute urine
B. Diabetes insipidus
C. Increased dissolved solutes
D. Inability to concentrate urine
Correct answer: C
Why: A high specific gravity reflects a high concentration of dissolved solutes, such as glucose, protein, radiographic contrast material, or marked dehydration.
Why the other options are wrong:
A — Dilute urine has low specific gravity.
B — Diabetes insipidus commonly produces low specific gravity.
D — Poor concentrating ability tends toward isosthenuria.
9
Which test is routinely used to monitor warfarin therapy?
A. Activated partial thromboplastin time
B. Prothrombin time expressed as INR
C. Thrombin time
D. Fibrinogen assay
Correct answer: B
Why: Warfarin affects vitamin K-dependent clotting factors and is monitored by PT standardized as INR.
Why the other options are wrong:
A — aPTT is commonly used for unfractionated heparin monitoring.
C — TT assesses conversion of fibrinogen to fibrin and is sensitive to heparin.
D — Fibrinogen alone does not monitor warfarin effect.
10
Which immunoglobulin class crosses the placenta most efficiently?
A. IgA
B. IgE
C. IgG
D. IgM
Correct answer: C
Why: IgG is actively transported across the placenta and provides passive fetal immunity.
Why the other options are wrong:
A — Secretory IgA is prominent in mucosal secretions and breast milk.
B — IgE mediates immediate hypersensitivity.
D — IgM is too large to cross the placenta efficiently.
11
A serum sample is visibly hemolyzed. Which analyte is most likely to be falsely increased?
A. Sodium
B. Potassium
C. Chloride
D. Calcium
Correct answer: B
Why: RBCs contain much higher potassium concentrations than plasma. Hemolysis releases intracellular potassium and can cause pseudohyperkalemia.
Why the other options are wrong:
A — Sodium is lower inside RBCs and is not typically falsely elevated by hemolysis.
C — Chloride is not the characteristic hemolysis-sensitive analyte.
D — Calcium is not commonly falsely increased from hemolysis.
12
Which organism is oxidase-positive and commonly produces blue-green pigment in culture?
A. Escherichia coli
B. Klebsiella pneumoniae
C. Pseudomonas aeruginosa
D. Acinetobacter baumannii
Correct answer: C
Why: Pseudomonas aeruginosa is oxidase-positive and may produce blue-green pyocyanin pigment.
Why the other options are wrong:
A — E. coli is oxidase-negative.
B — Klebsiella is oxidase-negative.
D — Acinetobacter is oxidase-negative.
13
The primary purpose of formalin fixation in histopathology is to:
A. Remove paraffin from tissue sections
B. Preserve tissue morphology and prevent autolysis
C. Stain cellular nuclei blue
D. Dehydrate tissue before embedding
Correct answer: B
Why: Formalin fixation cross-links proteins, limits autolysis and putrefaction, and preserves tissue architecture.
Why the other options are wrong:
A — Xylene removes paraffin during staining.
C — Hematoxylin stains nuclei.
D — Alcohols dehydrate tissue.
14
A direct antiglobulin test detects:
A. Free antibody in patient serum
B. Antibody or complement attached to patient RBCs in vivo
C. ABO antibodies in donor plasma
D. Platelet-associated antibodies only
Correct answer: B
Why: The DAT detects immunoglobulin and/or complement bound to RBCs in vivo.
Why the other options are wrong:
A — Indirect antiglobulin testing detects free serum antibody.
C — ABO antibodies are detected by reverse grouping.
D — DAT is not a platelet antibody test.
15
Which laboratory result most strongly supports iron deficiency anemia?
A. Increased ferritin
B. Increased transferrin saturation
C. Decreased total iron-binding capacity
D. Decreased ferritin
Correct answer: D
Why: Ferritin reflects iron stores and is typically reduced in iron deficiency anemia.
Why the other options are wrong:
A — Ferritin is usually low, not increased.
B — Transferrin saturation is reduced.
C — TIBC generally rises in uncomplicated iron deficiency.
16
A CSF specimen is cloudy with elevated neutrophils, high protein, and low glucose. Which condition is most likely?
A. Viral meningitis
B. Bacterial meningitis
C. Multiple sclerosis
D. Subarachnoid hemorrhage
Correct answer: B
Why: Neutrophilic pleocytosis, elevated protein, low glucose, and cloudy CSF support bacterial meningitis.
Why the other options are wrong:
A — Viral meningitis usually has lymphocytic predominance and normal glucose.
C — Multiple sclerosis may show oligoclonal bands.
D — Subarachnoid hemorrhage causes RBCs and xanthochromia.
17
Which quality-control rule is violated when one control result exceeds the mean by more than 3 standard deviations?
A. 1_2s
B. 1_3s
C. 2_2s
D. R_4s
Correct answer: B
Why: The 1_3s rule is violated when one QC result exceeds the mean by more than 3 SD; it is a rejection rule.
Why the other options are wrong:
A — 1_2s is generally a warning rule.
C — 2_2s requires two consecutive results beyond 2 SD on the same side.
D — R_4s requires a 4-SD difference between two controls in one run.
18
A patient has pH 7.28, pCO₂ 60 mmHg, and bicarbonate 27 mmol/L. What is the primary acid-base disorder?
A. Metabolic acidosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Respiratory alkalosis
Correct answer: C
Why: Low pH with elevated pCO₂ indicates respiratory acidosis. Bicarbonate is only slightly increased, consistent with limited acute compensation.
Why the other options are wrong:
A — Metabolic acidosis has reduced bicarbonate as the primary abnormality.
B — Metabolic alkalosis raises pH and bicarbonate.
D — Respiratory alkalosis lowers pCO₂ and raises pH.
19
Which culture medium is selective for Gram-negative enteric bacilli and differentiates lactose fermenters?
A. Blood agar
B. MacConkey agar
C. Chocolate agar
D. Sabouraud agar
Correct answer: B
Why: MacConkey agar inhibits many Gram-positive organisms and differentiates lactose-fermenting from non-lactose-fermenting Gram-negative bacilli.
Why the other options are wrong:
A — Blood agar is enriched and differential for hemolysis.
C — Chocolate agar supports fastidious organisms.
D — Sabouraud agar is used for fungi.
20
A platelet count is unexpectedly 28 × 10⁹/L, but the blood smear shows abundant platelet clumps. What is the most appropriate next step?
A. Report severe thrombocytopenia immediately
B. Repeat the count using a citrate-anticoagulated specimen
C. Perform a bone marrow examination
D. Add platelet-poor plasma to the specimen
Correct answer: B
Why: EDTA-associated platelet clumping causes pseudothrombocytopenia. Recollection in citrate often resolves the artifact.
Why the other options are wrong:
A — The automated count is unreliable when clumps are seen.
C — Bone marrow examination is not first-line for a specimen artifact.
D — Platelet-poor plasma does not resolve EDTA-dependent clumping.
