Blood Draw & Tubes

Question 1

True or False: Whole blood will clot if left in the tube for over 30 minutes.

Answer 1

False

Question 2

What is added to plasma to prevent clotting?

Answer 2

Anticoagulants

Question 3

How long will blood take to clot? What product is left behind?

Answer 3

20 - 30 minutes

Serum - blood cells trapped in a mesh of fibrin

Question 4

What is the name of the formation of WBCs and platelets in centrifuged test tube?

Answer 4

Buffy Coat

Question 5

True or False: Coagulation proteins are still present in the plasma even after it has been spun down.

Answer 5

True

Question 6

What is the liquid portion of clotted blood samples? Which coagulation protein is it lacking?

Answer 6

Serum; lacks Fibrinogen

Question 7

Venous blood samples make up what percentage of specimens submitted to the laboratory?

Answer 7

80%

Question 8

What procedure is performed when a venipuncture is contraindicated? What are some examples of patients they may be indicated for?

Answer 8

Capillary sample; Babies, small children, burn victims

***Capillary sample is composed of a mixture of arteriole, cap and venous blood in addition to interstitial and intracellular tissue.

Question 9

What does SST stand for in regards to blood tubes? What is it and what is its purpose?

Answer 9

Serum Separator Tube

It is an inert polymer barrier gel; once centrifuged it will act as a barrier between serum and clotted cells.

Question 10

Which color tube(s) fall into draw order group 1?

Answer 10

Light Blue

Question 11

Which color tube(s) fall into draw order group 2?

Answer 11

Plain red/red and gray SST
Yellow
Green

Question 12

Which color tube(s) fall into draw order group 3?

Answer 12

Purple/Lavender

Black

Question 13

Which color tube(s) fall into draw order group 4?

Answer 13

Gray

Question 14

What reagent does a light blue tube contain? What is its purpose?

Answer 14

Sodium Citrate; Anticoagulation

Question 15

What is the yield of a light blue tube?

Answer 15

Citrated Plasma

Question 16

What are the laboratory uses for a light blue tube?

Answer 16

Coagulation study

Question 17

True or False: A light blue tube must be filled to a 1:7 ratio of sodium citrate to blood.

Answer 17

False, it must be a 1:9 ration. Any less will be considered a short-draw and discarded.

Question 18

What color tube may contain Thrombin? What is the role of the Thrombin in this tube?

Answer 18

Red / Red and Gray SST

Thrombin acts as a clot activator

Question 19

What color(s) of tube(s) are used to yield Serum?

Answer 19

Red / Red and Gray SST

Yellow

Question 20

What is the laboratory use for a red tube blood draw?

Answer 20

Chemistry and Serology

Question 21

What is the reagent in a yellow topped tube?

Answer 21

Acid Citrate Dextrose(ACD)

Question 22

What is the laboratory use of a yellow topped tube?

Answer 22

HLA and paternity testing

Question 23

Which colored tube(s) CANNOT be used for Calcium, Sodium or Potassium testing? Why?

Answer 23

Purple/Lavender and Black

It contains EDTA

Question 24

What is the purpose of the EDTA reagent contained in purple/lavender and black tubes?

Answer 24

Purple/lavender and black tubes yield Plasma, therefore we do not want them to clot. EDTA will chelate the calcium(which is required for coagulation) in the sample, thus not allowing it to clot.