CPHT Order of Draw & Tube Additives 2

Question 1

What is the correct CLSI-recommended order of draw when collecting multiple tubes via venipuncture?

Accepted Answer

Blood cultures → Citrate → Serum/SST → Heparin → EDTA → Fluoride

Answer

EDTA → Citrate → Blood cultures → Serum → Heparin

Answer

Serum → Citrate → Heparin → EDTA → Fluoride

Answer

Citrate → Blood cultures → Serum → EDTA → Heparin

Question 2

Why must blood culture bottles be collected before all other tubes in the order of draw?

Accepted Answer

To prevent contamination from tube additives and maintain sterility

Answer

They require the largest blood volume

Answer

They must be incubated immediately after collection

Answer

Their anticoagulant degrades fastest at room temperature

Question 3

Why is the light blue (sodium citrate) tube collected before serum tubes in the standard order of draw?

Accepted Answer

Clot activator from serum tubes could carry over and falsely affect coagulation results

Answer

Citrate tubes require more inversion steps and take longer to process

Answer

Citrate tubes are more fragile and break if agitated by later draws

Answer

Sodium citrate expires more quickly than other tube additives

Question 4

When using a butterfly/winged infusion set, what must be done before collecting a sodium citrate tube?

Accepted Answer

Draw a discard tube to eliminate air from the tubing

Answer

Flush the tubing with normal saline first

Answer

Fill the citrate tube halfway, pause 30 seconds, then complete filling

Answer

Switch to a straight needle instead of a butterfly for citrate tubes

Question 5

In the order of draw, EDTA (lavender) tubes are collected immediately before which tube type?

Accepted Answer

Fluoride/oxalate (gray) tubes

Answer

Blood culture bottles

Answer

Serum separator tubes (SST)

Answer

Heparin (green) tubes

Question 6

What is the primary reason for following a specific order of draw during multi-tube collection?

Accepted Answer

To prevent additive carryover that could produce erroneous test results

Answer

To ensure tubes are collected as quickly as possible

Answer

To guarantee all tubes are completely filled to the fill line

Answer

To minimize the risk of hemolysis in all tubes equally

Question 7

A phlebotomist needs to collect a CBC, a BMP, and a PT/INR. What is the correct tube drawing order?

Accepted Answer

Light Blue (Citrate), Gold (SST), Lavender (EDTA)

Answer

Lavender (EDTA), Gold (SST), Light Blue (Citrate)

Answer

Gold (SST), Light Blue (Citrate), Lavender (EDTA)

Answer

Gold (SST), Lavender (EDTA), Light Blue (Citrate)