ASCP PBT key terms

The standardized sequence in which blood collection tubes are filled during a single venipuncture, designed to prevent additive carryover between tubes that could alter test results.

Transfer of a chemical additive from one collection tube into the next through the needle, potentially contaminating the later specimen and causing falsely altered results.

Ethylenediaminetetraacetic acid, an anticoagulant that binds calcium and is used in lavender-top tubes for hematology testing such as complete blood counts.

Rupture of red blood cells that releases hemoglobin and intracellular contents into plasma or serum, which can falsely elevate potassium and other analytes and is a common cause of specimen rejection.

A collection tube containing a clot activator and a gel barrier that separates serum from cells during centrifugation, commonly used for chemistry testing.

Predefined conditions under which a laboratory will not accept a sample for testing, such as unlabeled tubes, gross hemolysis, insufficient volume, or improper transport temperature.

The major blood group system based on presence or absence of A and B antigens on red cells and corresponding naturally occurring antibodies in plasma, determining transfusion compatibility.

The D antigen of the Rh blood group system; individuals lacking it are Rh-negative and may form anti-D antibodies after exposure to Rh-positive blood.

A compatibility test in which donor red cells are mixed with recipient serum to detect antibodies that could cause a transfusion reaction before blood is released.

A test that mixes a patient's serum with reagent red cells to detect unexpected antibodies against red cell antigens, performed before transfusion or during pregnancy.

A test using anti-human globulin reagent to detect antibodies or complement bound to a patient's own red cells in vivo, used to investigate hemolytic disease and transfusion reactions.

A waste product of muscle metabolism measured in serum to assess kidney filtration function; rising values suggest reduced glomerular filtration.

A measurement of urea nitrogen in blood that reflects kidney function and hydration status, often interpreted alongside creatinine.

An estimate of how much blood the kidneys filter per minute, usually calculated from creatinine, age, and sex to stage chronic kidney disease.

The range of test values expected in a healthy reference population, used to interpret whether a patient result is typical or abnormal.

A test result far outside normal limits that may indicate a life-threatening condition and requires prompt notification of the responsible caregiver.

A coagulation test measuring how long plasma takes to clot after addition of tissue factor and calcium, evaluating the extrinsic and common pathways.

International Normalized Ratio, a standardized calculation of prothrombin time against a reference thromboplastin, used mainly to monitor warfarin therapy.

A clotting test that evaluates the intrinsic and common coagulation pathways and is used to screen for factor deficiencies and monitor heparin therapy.

The number of platelets per volume of blood, measured to assess bleeding risk and to evaluate thrombocytopenia or thrombocytosis.

A panel of hematology measurements including red cell count, hemoglobin, hematocrit, white cell count, and platelet count used to screen for blood disorders.

The oxygen-carrying protein in red blood cells; its concentration in blood is a primary measure for detecting and classifying anemia.

The percentage of blood volume occupied by red blood cells, typically about three times the hemoglobin value in healthy individuals.

The percentage of newly released immature red cells in blood, used to judge whether bone marrow is responding appropriately to anemia.

An immunoglobulin produced by plasma cells that binds specifically to an antigen, forming the basis of humoral immune defense and serologic testing.

Any substance that can be recognized by the immune system and trigger an antibody response or T-cell activation.

A technique that uses an enzyme-linked antibody to detect or quantify an antigen or antibody through a color-producing reaction measured by a plate reader.

The set of procedures that monitor test performance by analyzing materials with known values, ensuring results stay within acceptable limits before patient samples are reported.

An external program in which a laboratory analyzes unknown samples and compares results with peer laboratories to verify analytical accuracy and meet regulatory requirements.

Documented, unbroken record of who collected, handled, and stored a specimen, required for forensic, employment, and legal drug testing.

Infection control practices applied to all patients, including hand hygiene and use of gloves and other barriers, to prevent transmission of bloodborne pathogens.

An injury in which a contaminated needle punctures the skin, requiring immediate washing and reporting because of risk of transmitting bloodborne infections.

A differential staining method that divides bacteria into gram-positive and gram-negative groups based on cell wall structure, guiding early antibiotic choice.

A laboratory procedure that grows organisms from a specimen and tests which antimicrobial agents inhibit them, guiding targeted therapy.

A visible cluster of microorganisms grown on solid medium from a single cell or group of cells, used to isolate and identify organisms.

Practices that prevent contamination of specimens, equipment, and wounds by microorganisms, including hand hygiene, sterile supplies, and disinfection of collection sites.