phlebotomy tube descriptions

Question 1

no additive

Answer 1

• tubes with no additives
• only serum or whole blood
• all clotting factors remain
• “waste tube”

Question 2

EDTA

Answer 2

Ethylenediaminetetraacetic acid

• CBC always drawn
• prevents coag. by binding or chelating calcium in the form of potassium or sodium salt
• blood smears must be made within 1 hr. b/c prolonged contact with EDTA may change staining charact.
• filled to top

Question 3

heparin

Answer 3

prevents coag. by inhibiting conversion of prothrombin to thrombin (anti-thrombin or neutralizes thrombin)

Question 4

sodium citrate

Answer 4

prevents coag. by binding calcium (inactivating it)

Question 5

potassium or ammonium oxalate

Answer 5

prevents coag. by precipitating calcium

Question 6

ACD

Answer 6

acid citrate dextrose

prevents coag. by binding calcium

Question 7

SPS

Answer 7

sodium polyanethol sulfonate

prevents coag. by binding calcium

Question 8

sodium fluoride or lithium iodoacetate

Answer 8

antiglycolytic agents- inhibits glycolysis

• glucose stability is preserved for 24 hours in iodoactate
• preserved for up to 3 days in sodium fluoride

Question 9

clot activator

Answer 9

substance that inhibits or enhances coag.

ie. substances that provide increased surface area for platelet activation (glass/silica particles/inert clays)

Question 10

SST

Answer 10

serum separator tube

• physical separation prevents the cells from continuing to metabolize substances (glucose) in the serum or plasma
• only cells go below barrier

Question 11

interference with assays

Answer 11

additive may contain a substance that is the same/or reacts the same as a substance that is being measured
ex. sodium heparin used in sodium determination

Question 12

removal of constituents

Answer 12

additive may remove constituent being measured
ex. oxalate additive removes calcium by forming an insoluble salt, calcium oxalate, therefore interfering with calcium determination

Question 13

effect on enzyme action

Answer 13

may affect enzyme reactions

ex. sodium fluoride destroys many enzymes

Question 14

alteration of cellular constituents

Answer 14

cellular constituents may be altered by an additive
ex. oxalate distorts the cell morphology to make RBCs become crenated, vacuoles appear in the granulocytes and bizarre forms of lymphs and monocytes appear rapidly

Question 15

incorrect amount of anticoagulant

Answer 15

too little = partial clotting may occur interfering with cell counts

too much = dilutes the blood sample interfering with certain quantitative measurements