Aliquoting to the Manual

Part of Clinical Laboratory (LAB) Training: Aliquoting, Labeling and Chain of Custody.

About 2 minutes. Free, in your language, no account needed.

Volume and count are both specified

The manual states how many aliquots, of what volume, into which tube type. All three are requirements.

An aliquot short by a third may not be enough for the assay. An extra aliquot nobody expected creates a reconciliation problem at the receiving laboratory.

Insufficient volume is common and must be recorded

Participants are sometimes hard to draw. You will receive tubes that cannot yield the full set.

Make the aliquots the manual prioritizes, in the order it gives. If it does not give an order, ask rather than choosing.

Record what you actually made. Three aliquots logged as four is a discrepancy that will surface when the receiving laboratory counts them.

Label before you fill, or after, but never in between

Both approaches are defensible if applied consistently. Mixing them is how aliquots get mislabeled.

The dangerous pattern is filling several tubes and labeling them afterward from memory of the order. That relies on recall at exactly the moment you are busiest.

Labels have to survive the conditions

A label that peels at minus eighty is a lost sample. Ink that fades under liquid nitrogen vapor is a lost sample.

Use the label stock the manual specifies. If you substitute because you ran out, that is a deviation worth recording, not a quiet swap.

Check the label against the parent tube

Every aliquot inherits its identity from the tube it came from. One transcription error propagates into every aliquot you make from it.

Read the parent label again before you start filling. Not from memory of reading it a minute ago.

The count is the control

At the end, count what you made and reconcile it against what the log says you should have.

A count that does not balance is caught here cheaply, while the parent tube is still on the bench and the question is answerable. Caught at the receiving laboratory a week later, it is an investigation.