5 Tube Selection and Order-of-Draw Practice Free Online FlashCards

What should determine which collection tube you select?

Select the tube by the specimen and additive required by the performing laboratory, not by color alone.

How is serum prepared from a blood sample?

Serum is collected in a tube that allows blood to clot, then separated from the cells.

Which common tube is typically selected for a CBC?

Lavender or purple EDTA tubes are commonly used for a CBC and many hematology tests.

Which tube is commonly used for PT/INR and aPTT, and what fill concern matters?

A light-blue sodium citrate tube is commonly used. Fill it to the required volume to maintain the correct blood-to-additive ratio.

Is a royal-blue cap alone enough to select a trace-element tube?

No. Royal-blue tubes may be plain, contain EDTA, or have another additive; confirm the exact tube specified by the laboratory.

What is first in the standard venous order of draw?

Blood cultures or other sterile specimens are collected first.

How should additive tubes be mixed after collection?

Mix additive tubes promptly and gently, using the number of inversions specified by the manufacturer or facility. Do not shake them.

Name one potential problem caused by vigorous tube shaking.

Vigorous mixing can damage red cells and cause hemolysis.

What should happen to a serum tube before centrifugation or transport?

Allow it to clot as directed before centrifugation or transport; do not treat it as an anticoagulated plasma tube.

What identification check helps prevent specimen mix-ups?

Identify the patient and label specimens at the collection site according to facility policy; confirm the label matches the requisition.

How should a visibly underfilled light-blue tube be handled?

Do not assume it is acceptable: underfilling can alter the blood-to-citrate ratio. Follow laboratory policy on rejection or recollection.

How is plasma prepared from a blood sample?

Plasma is collected in a tube containing an anticoagulant, then separated from the cells.