Lesson 6-2

What safety measures must be observed to avoid accidental needlesticks?

1. Use safety needles and needle holders 2. Immediately discard used needles into a sharps container 3. Never attempt to recap a needle

What is the order of draw and why is it important?

A set of rules governing the collection order of specimens and tube use during a venipuncture. Observing the order of draw minimizes the possibility of additives in collection tubes contaminating other tubes and cause problems in the analyses.

What are the most commonly tested body fluids?

Blood and urine

What is the proper order of draw?

Blood culture bottles, yellow top, light blue top, red/gray top, green top, lavender or pink top, royal blue top, gray top.

How is blood collected for procedures requiring plasma?

Blood is collected into a tube containing one of the various anticoagulants that prevent blood clotting.

How is blood collected for procedures requiring serum?

Blood is collected into a tube without anticoagulants and is allowed to clot

How can the timing of specimen collection affect test results?

Concentrations of some blood constituents exhibit diurnal variation. Others change value after eating and requiring a fasting specimen.

How does freezing whole blood affect the specimen?

Freezing causes lysis of blood cells releasing intracellular constituents.

What PPE must be worn when collecting and processing specimens?

Gloves, full face protection, and a buttoned fluid resistant laboratory coat

What can cause hemolysis of a specimen?

Improper venipuncture technique, over-centrifugation, accidental freezing, excessive shaking of a blood sample, and forcing blood through a small bore needle

How can test results be affected by a henolyzed specimen?

Lysed cells release substances such as hemoglobin, potassium, and cellular enzymes into the serum or plasma

What are four types of tubes (cap colors) that can be used to collect serum?

Plain red-top tubes, red/gray top tubes with serum separator gel, gold top tubes with serum separator gel, and orange top tubes with thrombin.

What is the difference between serum and plasma

Plasma contains all of the blood plasma constituents including the coagulation proteins. Serum contains the plasma constituents minus the coagulations proteins.

Discuss why quality assessment procedures are important in collecting and processing specimens for clinical chemistry.

The quality of the specimen is of utmost importance to ensure the quality of the results.