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Clinical Chemistry Laboratory

About the Lab

The Clinical Chemistry laboratory provides routine and state of the art specialized assays for patient care. The laboratory is open and staffed 24 hours a day, seven days a week, and tests of an urgent nature are available around the clock. One or more of the laboratory directors are available at all times for consultation and/or to facilitate use of the laboratory's services.

Clinical Chemistry laboratories generate over three million test results a year, offering assays for nearly 200 different clinically important constituents. Assays are carried out using a wide variety of techniques ranging from fully automated instruments to high performance liquid chromatography and tandem mass spectrometry.


Routine Tests

Most tests that are required urgently are performed, continuously, with short turn around time, on automated, high volume rapid analyzers. These include, but are not limited to glucose, BUN, electrolytes, Ca, P, liver function tests, cardiac markers, CSF glucose and protein, and measurement of drugs frequently involved in poisonings as well as commonly monitored therapeutic drugs.

Critical Values

Test results that may require urgent clinical intervention are immediately called to the patient's physician or other appropriate caregiver. Selected routine chemistry tests are also performed at several satellite laboratories located in close proximity to YNHH and YMG outpatient clinics.

Specialized Tests

The laboratory performs a wide variety of highly specialized assays, many of which are not generally available in other Connecticut Hospitals. While many of these are performed daily, some less frequently requested tests are done on scheduled days. However, exceptions are made, following consultation, when required for optimal patient care.

Clinical Pharmacology and Toxicology

Assays are performed for monitoring therapy with various antiepileptic, cardiac chemotherapeutic, and immunosuppressive drug, and for evaluating suspected poisonings. Assays are available for over 40 different pharmacological agents, some not available in most hospital based clinical laboratories, with many available 24 hours/day. Immunosuppressive drugs (cyclosporine, tacrolimus and sirolimus) are analyzed using state of the art tandem mass spectrometry. We also offer stat panels for measurement of important toxic drugs including drugs of abuse, and are currently the only hospital in Connecticut that performs specific identification and quantitation of methanol and toxic glycols.


Most tests of thyroid, parathyroid, adrenal, pituitary and gonadal function are available on site and are performed using highly specific immunoassays. Tests for the evaluation of adrenal medullary tumors (urinary free catechol amines and VMA), and neural crest tumors (urinary dopamine and HVA) are performed using state of the art HPLC procedures.

Intaoperative PTH

Assays of parathormone activity in blood and resected tissues is performed on site, in real time in the operating room to follow the progress of parathyroid surgery. YNHH was among the first hospitals to offer this service.

Other Specialized Assays

Highly sensitive whole blood lead assays to diagnose acute toxicity as well as chronic lead exposure are performed using atomic absorption spectrometry (graphite furnace). To assist with acute obstetrical management, fetal fibrinectin and amniotic fluid lecithin: sphingomyelin (L/S) ratio assays are available at all times.

Video Series by Dr. Joe El-Khoury

Ending Pseudohyponatremia

Dr. Joe El-Khoury discusses pseudohyponatremia in clinical chemistry testing.

Video by Joe El-Khoury


  • Assistant Professor; Medical Director, Chemical Pathology, Laboratory Medicine; Medical Director, Laboratory IT Services, Laboratory Medicine; Associate Director, ACGME Chemical Pathology Fellowship, Laboratory Medicine

  • Professor of Laboratory Medicine, of Neurosurgery, and of Cellular and Molecular Physiology; Vice Chair for Education, Department of Laboratory Medicine; Director of Medical Education, Department of Cellular and Molecular Physiology; Thread Leader, Physiology, Office of Education; Associate Director, Clinical Chemistry Laboratory, Yale-New Haven Hospital