Phlebotomy Tubes for NHA Exam
Questions with Correct Answers
Lavendar Top Tube Additive ✔✔Contains the anticoagulant ethylenediaminetetraacetic acide
(EDTA). EDTA inhibits coagulation by binding to the calcium present in the specimen. Tubes
must be filled at least 2/3 full and inverted 8x.
Lavendar Top Tube Tests ✔✔CBC, H&H, ESR, Sickle Cell Screening
Light-Blue Top Tube Additive ✔✔Contains the anticoagulant Sodium Citrate, which prevents
coagulation by binding to the calcium in the specimen. Sodium Citrate preserves the coagulation
factors. Must be completely filled and inverted 3-4x
Light-Blue Top Tests ✔✔PT, APTT (or PTT), Fibrinogen Degradation Products (FDP),
Thrombin Time (TT), Factor assays, Bleeding Time (BT)
Green Top Tube Additive ✔✔Contains anticoagulant Heparin combined with sodium, lithium,
or ammoniumion. Heparin works by inhibiting thrombin in the coagulation cascade. It is not
used for hematology because heparin interes with the Wright's stained blood smear. Invert 8x
Questions with Correct Answers
Lavendar Top Tube Additive ✔✔Contains the anticoagulant ethylenediaminetetraacetic acide
(EDTA). EDTA inhibits coagulation by binding to the calcium present in the specimen. Tubes
must be filled at least 2/3 full and inverted 8x.
Lavendar Top Tube Tests ✔✔CBC, H&H, ESR, Sickle Cell Screening
Light-Blue Top Tube Additive ✔✔Contains the anticoagulant Sodium Citrate, which prevents
coagulation by binding to the calcium in the specimen. Sodium Citrate preserves the coagulation
factors. Must be completely filled and inverted 3-4x
Light-Blue Top Tests ✔✔PT, APTT (or PTT), Fibrinogen Degradation Products (FDP),
Thrombin Time (TT), Factor assays, Bleeding Time (BT)
Green Top Tube Additive ✔✔Contains anticoagulant Heparin combined with sodium, lithium,
or ammoniumion. Heparin works by inhibiting thrombin in the coagulation cascade. It is not
used for hematology because heparin interes with the Wright's stained blood smear. Invert 8x
