💉 The Order Of Draw

• Blood samples must be drawn by phlebotomists in a specific order. This is important to avoid cross-contamination of the sample by additives found in different collection tubes. Cross contamination can occur when blood in an additive tube comes in contact with a needle and when blood is transferred from a syringe into tubes.

• Filling tubes in wrong order will cause interference in specimen testing from cross contamination, tissue thromboplastin and microorganisms.

• And improperly collected or contaminated specimen can give spurious results (incorrect results). Results may not be reported if it is clear that the result is invalid. 

• This order of draw applies for all specimens collected by syringe, tube holder, or into pre evacuated tubes.

• Let the vacuum in the tube fill the blood up to its level. 

• Do not press the syringe plunger as this will lead to hemolysis.

•  Gently invert according to the instruction and be sure that the entire inner surface of the blood collection tube is coated with blood while mixing.