Types of Specimens Whole Blood Plasma Serum Stool Urine Body Fluids Sputum Cultures…to name a few
Whole Blood Represents blood as it circulates through the body Contains erythrocytes, leukocytes, and platelets Sodium EDTA Uses: CBC, Blood Bank, Flow cytometry, BNP, Hemoglobin A1c
Plasma One type of liquid portion of the blood HAS NOT CLOTTED! Sodium citrate Contains fibrinogen, and clotting factors Uses: PT, APTT, Fibrinogen, Dimer
Plasma Liquid portion of the blood Sodium or lithium heparin Has not clotted! Uses: Rapid chemistry ie, glucose, electrolytes
Serum Tube has been allowed to clot before centrifugation No clotting factors or fibrinogen present Liquid portion of the blood Contains proteins, enzymes, organic and inorganic chemicals and antibodies Uses: Chemistry, Therapeutic drug levels, Immunology, Blood Bank Has no additive
Serum Same analytes as before Gel: activates clot and acts as a barrier Popular for ease of use Not suitable for TDMs Not recommended for Transfusion testing
Why is this important? “The quality of any test result is only as good as the specimen that is tested!”
We can monitor testing personnel through competency testing…We can monitor instruments and procedures by means of calibrations and controls…BUT, we can’t monitor specimen collection very well!!
Specimen Criteria Specimens must be drawn in the correct tube and they must be filled to the proper level Timely delivery to laboratory is critical Anticoagulant additives can contaminate subsequent tubes Some additives change the shape or size of the cells Additives can give falsely elevated results
Specimen Labeling Proper specimen labeling is essential Correct patient identification: Two forms of identification is best….birthdate, medical record number, full name Patient preparation…fasted, dose time, medications, transfusion status Time of collection Collector’s identification
Specimen Problems Clotted specimens collected with anticoagulant Hemolyzed specimens Lipemic specimens Icteric specimens IV fluid contamination in specimens…Never collect above an IV line !
Non-Blood Specimens Must always be properly labeled Must be collected in a sterile container Volume of collection is critical to the test Transport to lab must be timely If held, storage requirements must be met
What do the results mean? Complete Blood Count (CBC) WBCWhite blood cell count RBCRed blood cell count HGBHemoglobin HCTHematocrit MCVMean cell volume-cell size MCHMean cell color MCHCMean cell hemoglobin concentration PLTPlatelet count RDWRed cell population variation
Prothrombin Test Activated Partial Thromboplastin Time PT Measured in seconds How long to clot Monitors oral anticoagulants INR RatioCompares therapies and instrumentation PTT Measured in seconds How long to clot Monitors IV anticoagulants
Urinalysis Recommended volume is 12 mls Specimen is tested with a dipstick for: Glucose, Ketones, Blood, pH, Bilirubin, Urobilinogen, Leukocytes, Protein Specimen is centrifuged and sediment is examined with microscope to report cells, and other structures: crystals, casts, bacteria, yeast, parasites and more! Color and appearance (clear, hazy, cloudy, bloody)
Cultures Plated on differential and selective media to grow the organisms present Gram stain is done except on urine and stool (too much normal flora present) Organisms determined to be pathogenic are tested for sensitivity to antibiotic drugs Cultures take from 2 – 30 days or more Fungal and viral cultures are kept the longest