Richard A. Marlar, Ph.D.

photo of richard marlar

Visiting Professor



  • Thrombophilia Testing
  • Protein C and Protein S Deficiencies
  • Concept of “Deficiency” in Hemostasis
  • Quality Assurance Issues in Thrombosis and Hemostasis

Education and Certification Information

NIH and AHA Fellowships
Biochemistry of Hemostasis
Mentor, John H. Griffin
Scripps Clinic and Research Institutes
La Jolla, CA

PhD (Physiology and Biochemistry):
Wayne State University
Mentor, Dr. Walter H. Seegers
Detroit, MI

MS (Zoology and Chemistry)
University of North Dakota
Grand Forks, ND

BSc (Zoology)
Humboldt State University
Arcata, CA

Selected Publications:

  • Marlar RA, Gausman JN. Assessment of hereditary thrombophilia - Performance of Protein C (PC) testing. In: Haemostasis and Thrombosis: Methods and Protocols, Eds: Favaloro & Lippi. New York; Springer, 2016.

  • Marlar RA, Clement B, Gausman J. APTT monitoring of Unfractionated Heparin therapy: Issues and Recommendations. Sem Thromb Hemost, e-publication, 2016.

  • Brisset AC, Fernandez A, Krause M, Rathbun S, Marlar R, Korte W. The PiCT® test, a reliable alternative to the aPTT in UFH therapy management – results from a prospective multicenter cohort study. J Thromb Hemost, 14:1-7, 2016.

  • Rathbun S, Tafur A, Grant R, Esmon N, Mauer K, Marlar RA: Comparison of methods to determine rivaroxaban anti-factor Xa activity. Thromb Res 125:394-397, 2015.

  • Marlar RA, Gausman JN: Laboratory testing issues for protein C, protein S, and antithrombin. Internat J Lab Hem 36:289-295, 2014.

  • Marlar RA, Gausman JN, Engel JW: Validation of hemostasis and coagulation assays: Recommendations and guidelines. Sem Thromb Hemost 40:186-195, 2014.

  • Johnson PN, Benefield EC, Phi-Yen NB, Gausman JN, Marlar RA, Gessouroun MR: Fondaparinux monitoring: Need for a local fondaparinux-calibrated anti-factor Xa assay. J Ped Pharmacol Therap. 18:318-319, 2013

  • Marlar RA: Hemostasis Test Validation, Performance and Reference Intervals. Chapter 2. In: Olson J, Kitchen S, Preston E, eds. Quality in Laboratory Hemostasis and Thrombosis. Blackwell Publishers, 2nd edition, 2013.

  • Marlar RA, Gausman JN: The optimum number and types of plasma samples necessary for an accurate APTT-based heparin therapeutic range. Arch Path Lab Med 137(1):77-82, 2013.

  • Marlar RA, Seywerd K: Laboratory Evaluation of Acquired Coagulation Disorders. In: Kottke-Merchant K. and Davis B., eds. Laboratory Hematology Practice, Wiley-Blackwell Press, Chapter 37, 2012.

  • Marlar RA: Are laboratory results (phenotype) indicative of a true genotype abnormality? Am J Clin Path 137:173-175, 2012.

  • Marlar RA, Gausman JN: Protein S abnormalities: A diagnostic nightmare. Am J Hematol 86:418-421, 2011.

  • Marlar RA: Accurate testing of dysfunctional molecules: Potential for missing the diagnosis. Int J Lab Hematol 33:451-453, 2011.

  • Gausman JN, Marlar RA: Inaccuracy of a ‘spiked curve’ for monitoring unfractionated heparin therapy. Am J Clin Path 135:870-876, 2011.

  • Marlar RA, Fink L, Miller J: Laboratory approach to thrombotic risk. In: Henry’s Clinical Diagnosis and Management by Laboratory Methods, 22nd edition, Eds: McPherson and Pincus, New York, Saunders, chapter 41, 2011.

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Richard A. Marlar on PubMed