3 Specimen Processing and Centrifugation Free Online FlashCards

What is the purpose of specimen processing?

Specimen processing covers the steps between collection and testing that preserve a sample’s identity and condition.

What should be verified on a specimen label?

Use the facility’s required patient identifiers and check that the specimen label matches the requisition. Unlabeled or mismatched specimens may need to be rejected.

How should potentially infectious specimens be handled and transported?

Treat potentially infectious specimens as biohazards. Use appropriate protective equipment and secure primary containers in suitable secondary containment during transport.

How should additive-containing blood tubes be mixed?

Gently invert additive-containing tubes as directed by the manufacturer or laboratory; do not shake them.

How do serum and plasma differ?

Serum comes from blood that has clotted. Plasma comes from blood collected with an anticoagulant and retains clotting factors.

Why can’t one storage temperature be used for every specimen?

Temperature and packaging requirements vary by test: specimens may need room temperature, refrigeration, freezing, or other special handling. Follow the current test instructions.

What can make a specimen unacceptable to a laboratory?

Reasons include identification problems, the wrong specimen or container, insufficient quantity, leakage, improper transport, or a specimen outside its stability limit. Follow authorized procedures; do not relabel or alter it without authorization.

What equipment and tube checks should precede centrifugation?

Use compatible tubes and rotor components, avoid cracked or damaged tubes, keep the bowl and tubes dry, and ensure the rotor is properly seated.

How should centrifuge tubes be balanced?

Place tubes of equal mass opposite one another and load positions symmetrically. Use a suitable balance tube when needed, and do not run a visibly unbalanced rotor.

Why is RCF preferred over RPM for specifying a centrifuge run?

Prefer relative centrifugal force (RCF) because the same RPM produces different forces in rotors with different radii.

What relationship converts RPM and radius to RCF?

$\mathrm{RCF}=1.118\times10^{-5}\times r\times\mathrm{RPM}^{2}$, where $r$ is the rotational radius in centimeters.

What should you do if a centrifuge behaves abnormally?

Keep the lid closed during operation. If the centrifuge vibrates or makes unusual noise, stop it according to procedure and investigate only after the rotor stops completely.