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Laboratory (Blood & Specimen) Services

For Medical Professionals

We provide a broad range of tests in the following areas:

Anatomic Pathology

  • Surgical
  • Cytopathology


  • Blood bank
  • Coagulation
  • Immunology


  • Chemistry
  • Hematology
  • Microbiology
  • Urinalysis

Certification and Accreditation

Greenwich Hospital Laboratory is a licensed and accredited laboratory that provides sub-specialized expertise, exceptional service and innovative solutions to our customers.

  • College of American Pathologists (CAP) # 1193301
  • College of American Pathologists (CAP) # 1193303
  • College of American Pathologists (CAP) # 7221138
  • State of Connecticut Department of Public Health: BB-1011
  • State of Connecticut Department of Public Health: HP-0208
  • State of Connecticut Department of Public Health: HP-0280
  • State of Connecticut Department of Public Health: HP-0324
  • New York State Department of Health: PFI 7169
  • New York State Department of Health : PFI 8307

Specimen Quality

When blood or specimens are obtained at a physician’s office, these guidelines should be followed:

Clinical specimens for analysis should be collected in appropriate containers, at appropriate times, and with patients in the appropriate state (e.g., prior to receiving antibiotics, fasting, etc).

Specimens should meet applicable standards for acceptability (e.g., no hemolysis, clotting) and should be transported to the laboratory in a time frame and under conditions that do not interfere with analysis.

Specimen quality is fundamental for the quality of the tests. The most common specimen quality issues and their implications are:

  • Hemolysis. Some analytes may be reported erroneously if the serum is not promptly removed from the clot, or if the barrier tube is not centrifuged after the clot has formed. Major discrepancies are low glucose, high potassium and LD.

    Additionally, if hemolysis takes place during initial processing and venipuncture, or if prolonged contact with the clot takes place, elevation in cholesterol, creatinine, iron, phosphorus, calcium and most enzymes will be found. Hemolyzed hematological specimens are unsuitable for testing.

  • Quantity Not Sufficient (QNS). Most hematology tests require a full tube of blood. This is because there is a defined quantity of anticoagulant in each tube and the ratio of this to the blood volume must be exact to ensure quality results. Particularly important are blue-top tubes used for Blood Coagulation tests. For prothrombin time, activated partial thromboplastin time and fibrinogen determinations exactly 4.5 mL of blood must be obtained (a full tube).

For CBCs, a "short draw" lavender tube will result in red cell crenation, reduced MCV and hematocrit, and possible changes in leukocyte morphology, platelets and total leukocyte counts.

  • Clotted specimens. All hematological testing utilizes anticoagulated blood. For blood counts, a lavender-top tube containing the anticoagulant EDTA is required. All specimens should be collected and the tube filled to the limit of the vacuum. Clotted samples, either macroscopic or microscopic in nature, cannot be processed for CBC testing, as such results will produce false leukopenia, low red cell counts, and aberrant red cell indices. Similarly, small clots found in blue top tubes (for coagulation tests) will result in falsely prolonged test results.
  • Icteric. If the specimen is deeply icteric, falsely elevated cholesterol results may be obtained. Lipemic. Lipemia can falsely elevate ALT and AST. Additionally, it can indicate that the patient did not adequately fast for 12-18 hours before having the specimen collected. In this situation, glucose and triglycerides will be elevated.
  • Decreased Bilirubin. Bilirubin is photodegradable. Prolonged exposure of the specimen to bright light will produce depressed results.
  • Decreased CO2 Levels. Carbon dioxide levels are decreased if the specimen is not tested promptly. CO2 escapes from red cells in vitro, at a rate proportional to time. This can be minimized by keeping the stopper on the tube and by refrigeration.
  • Poor Cell Preservation. Blood cells, particularly leukocytes, become fragile and can be distorted morphologically if the specimen is older than 24 hours. In such situations, a reliable differential white cell count cannot be performed.

Turnaround Time

Greenwich Hospital Laboratory is dedicated to providing accurate, reliable and clinically relevant data. Because 95 percent of lab analysis is done on the premises and because the specimens do not travel many miles, even from our satellite stations, our expected turn-around-time (TAT) for routine tests is 24 hours.

Quality Assurance

The laboratory formally monitors its ongoing processes and operations and is committed to continuous quality improvement.We conform to all regulatory standards set by law and adhere to higher standards for quality as exemplified by our accreditations by the College of American Pathologists, the states of New York and Connecticut, and The Joint Commission.

The laboratory is committed to compliance with all applicable State and Federal guidelines, including those set by the Clinical Laboratory Improvement Act (CLIA), the Centers of Medicare & Medicaid Services (CMS) and HIPAA Privacy regulations.

Laboratory orders must be placed by a licensed provider, physician’s signature required.

Laboratory requisition form