CAP Pro Course - Hematology - Platelet Testing, Morphology, and Disorders (2026 & 2027)

Author: Margaret Reinhart, MS, MLS(ASCP)
Reviewer: Laurie Bjerklie, MA, MLS(ASCP)CM

Continuing Education Credits

Objectives

  • Describe megakaryopoiesis leading to the formation of platelets, as well as the various functions and roles of platelets in hemostasis.
  • Describe proper blood collection methods used for platelet analyses.
  • Outline the basic automated platelet counting and sizing methods, and describe their utility.
  • Describe methodologies for microscopic evaluation and estimation of platelets, as well as platelet function testing methods.
  • Recognize abnormal, unexpected, and false platelet test results, as well as those that do not correlate with other data; describe appropriate actions to take in such cases.
  • Correlate results of platelet tests with various quantitative and qualitative platelet disorders.

Course Outline

  • Describe megakaryopoiesis leading to the formation of platelets, as well as the various functions and roles of platelets in hemostasis.
      • Platelet Production
      • The Role of Platelets in Hemostasis
      • Platelet Structure and Function
      • Which of the following choices best describes how platelets are formed?
      • Which of the following statements accurately describes the correlation between platelet quantity, functionality, and primary hemostasis?
      • Platelets are produced by which of the following precursor cells?
  • Describe proper blood collection methods used for platelet analyses.
      • Specimen Collection, Handling, and Storage
      • Preparation for Manual Platelet Microscopic Evaluation
      • Which of the following tube types is used for platelet function testing?
      • A CBC performed on a patient shows a slightly decreased platelet count. The attending physician responds by requesting platelet function tests on that...
      • A manual review of a patient sample is required before a platelet count can be released on a potentially critical patient. What is the appropriate way...
  • Outline the basic automated platelet counting and sizing methods, and describe their utility.
      • Automated Platelet Counting and Sizing
      • Electronic Impedance Methods
      • Light Scatter Methods
      • Optical Scatter (Fluorescence)/Flow Cytometric Methods
      • Which of the following statements regarding mean platelet volume (MPV) is true?
      • A blood specimen for platelet function assay has been collected on a patient. The specimen cannot be delivered immediately to the laboratory. How shou...
      • A clinician called about a patient and wanted to know their platelet count and variation in their platelet sizes. Which CBC values would you refer the...
  • Describe methodologies for microscopic evaluation and estimation of platelets, as well as platelet function testing methods.
      • Microscopic Observation of Peripheral Blood Smears
      • Estimating Platelet Concentration From a Peripheral Smear
      • Routine Tests of Platelet Function
      • Summary of Platelet Tests and Methodologies
      • An outpatient's platelet count is flagged, and a manual count is recommended to determine if it corresponds with the automated count of 720 × 109...
      • A manual platelet estimate is performed after the automated platelet count of 53 × 109/L is flagged. The estimate is 50 × 109/L. What action...
      • Which of the following is not a platelet activator (agonist) commonly used when performing platelet aggregation and adhesion studies?
      • A patient being treated for iron deficiency anemia requires a manual smear review for platelet count. An increased number of small platelets is observ...
  • Recognize abnormal, unexpected, and false platelet test results, as well as those that do not correlate with other data; describe appropriate actions to take in such cases.
      • Automated Platelet Testing: Recognition of Abnormal, Unexpected, or Spurious Results
      • Platelet Evaluation on Stained Blood Smears: Platelet Arrangement
      • Platelet Evaluation on Stained Blood Smears: Platelet Size
      • Platelet Evaluation on Stained Blood Smears: Platelet Granulation
      • Table 3. Platelet Evaluation on Wright-Stained Blood Smears (1000X)
      • Platelet Function Testing: Sources of Error
      • A medical laboratory science student was reviewing a manual smear. Which of the following morphologic descriptions most accurately describes the plate...
      • A medical laboratory scientist evaluates a patient's Wright-stained peripheral blood smear and observes the field image shown to the right. What can c...
      • A low platelet count is flagged. The medical laboratory scientist makes a Wright-stained smear to evaluate the platelets. Which of the following is no...
  • Correlate results of platelet tests with various quantitative and qualitative platelet disorders.
      • Platelet Test Results and Association with Clinical Disorders
      • Clinical Conditions Associated With Thrombocytopenia Due to Decreased Platelet Production
      • Clinical Conditions Associated With Thrombocytopenia Due to Destruction of Platelets or Increased Platelet Utilization (Platelet Consumption)
      • Clinical Conditions Associated With Thrombocytosis
      • Clinical Conditions Associated With Platelet Dysfunction
      • Clinical Conditions Associated With Alterations in MPV
      • A patient with thrombocytopenia was diagnosed with a May-Hegglin anomaly. What other platelet abnormalities, if any, can be found in these patients?
      • Platelet function tests are ordered on a patient with a normal platelet count. The platelet aggregation studies were abnormal. Which of the following ...
      • Which of the following conditions involves decreased platelet production in the bone marrow, resulting in thrombocytopenia?
  • References
      • References

Additional Information

Level of Instruction: Intermediate
Intended Audience: Medical laboratory scientists, medical laboratory technicians, laboratory supervisors, and laboratory managers. This course is also appropriate for MLS and MLT students and pathology residents.
Author Information: Margaret Reinhart, MS, MLS(ASCP) is a senior lecturer in Biological Sciences at the University of the Sciences in Philadelphia, PA, where she teaches hematology, clinical immunology, parasitology, and other related courses. She was the MLS Program Director there for 30 years. She is also an adjunct instructor in Hematology at Pennsylvania Hospital, Philadelphia, PA. She holds a Masters Degree in Biology and Health Care Administration.
The author has no conflict of interest to disclose. 
Reviewer Information: Laurie Bjerklie, M.A., MLS(ASCP)CM, is a Lead Education Developer. She earned a B.S. in Medical Laboratory Science from the University of North Dakota and an M.A. in Curriculum and Instruction from Saint Xavier University. She has over 15 years of experience in higher education and has held program director and faculty positions in both MLT and MLS programs.

This course is part of the CAP Competency Assessment Hub.

See other included Pro courses

See other included instrument checklists
Request Info