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School of Medicine
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William Alex Clarke, Ph.D.
Director, Clinical Toxicology, The Johns Hopkins Hospital
Professor of Pathology
Research Interests: Drug assay development; Pharmacogenomics; Clinical toxicology; Therapeutic drug monitoring
Dr. William Clarke is an associate professor of pathology at the Johns Hopkins University School of Medicine. His research focuses on the development of analytical methods for drug analysis, clinical mass spectrometry, and devices for point-of-care testing. Dr. Clarke serves as the director of Clinical Toxicology as well as Critical and Point-of-Care Testing Program at The Johns Hopkins Hospital.
His team's current projects include qualitative screening for antiretroviral drugs and substances of abuse in various HIV- prevention clinical trials, development and validation of mass spectrometry methods for clinical analysis, and development of clinical assays for use on microfluidic platforms.
Dr. Clarke received his B.S. in Chemistry from the University of Nebraska at Kearney and his Ph.D. in Analytical Chemistry from the University of Nebraska-Lincoln, as well as an M.B.A. from the Carey School of Business at Johns Hopkins University. He completed a post-doctoral fellowship in Clinical Chemistry at the Johns Hopkins School of Medicine.
- Director, Clinical Toxicology, The Johns Hopkins Hospital
- Director, Critical and Point-of-Care Testing, The Johns Hopkins Hospital
- Professor of Pathology
Departments / Divisions
- Pathology - Clinical Chemistry
- B.S., University of Nebraska (Kearney) (Nebraska) (1993)
- Ph.D., University of Nebraska (Lincoln) (Nebraska) (2000)
Research & Publications
Dr. Clarke's research interests primarily involve the development of analytical methods for drug analysis. This includes the development and implementation of tandem mass spectrometry and high resolution-accurate mass (HRAM) spectrometry method for measurement of multiple drugs in a single sample, as well as investigation of alternative matrices for drug testing. In addition, he is interested in the application of pharmacokinetic measurements, along with pharmacogenetic testing, to clinical management of patients.
Active projects in his lab include include qualitative screening for antiretroviral drugs and substances of abuse in various HIV- prevention clinical trials, development and validation of mass spectrometry methods for clinical analysis, and development of clinical assays for use on microfluidic platforms. He and his team are also investigating ways to improve the robustness and throughput of LC-MS methods in the clinical laboratory by the evaluation of newly developed technologies and alternative approaches to LC-MS method development.
Lab Website: Advanced Clinical Chemistry Diagnostics Laboratory
Technology Expertise KeywordsLC-MS/MS, chromatography, mass spectrometry, immunoassay
Olson MT, Breaud A, Harlan R, Emezienna N, Schools S, Yergey AL, and Clarke W. "Alternative Calibration Strategies for the Clinical Laboratory: Application to Nortriptyline Therapeutic Drug Monitoring, Clin Chem, 2013; 59 (6): 920-927.
Marzinke MA, Breaud A, Parsons TL, Cohen MS, Piwowar-Manning E, Eshleman SH, and Clarke W. "The Development and Validation of a Method Using High-Resolution Mass Spectrometry (HRMS) for the Qualitative Detection of Antiretroviral Agents in Human Blood", Clin Chim Acta, 2014; 433: 157-1681)
Clarke W. "What is Needed for Optimal Therapeutic Drug Monitoring", Bioanalysis, 2014; 6 (2): 113-115.
Marzinke MA, Petrides AK, Steele K, Schweitzer MA, Magnuson TH, Reinblatt SP, Coughlin JW, and Clarke W. "Decreased Escitalopram Concentrations Post Roux-en-Y Gastric Bypass Surgery", Ther Drug Monit, 2015; 37 (3): 408-412.
Olson MT, Baxi A, ElNaggar, M, Umbricht C, Yergey AL, and Clarke W. "Morphologically Compatible Mass Spectrometric Analysis of Lipids in Cytological Specimens", J Am Soc Cytopath, 2016; 5 (1): 3-8.
Contact for Research Inquiries
1800 Orleans Street
Sheikh Zayed Tower, B-1020F
Baltimore, MD 21287 map
Academic Affiliations & Courses
Graduate Program Affiliation
Biochemistry, Cellular and Molecular Biology