Question 1

An analytical balance is used to weigh certified material for an in-house calibrator. At start-up it ran its internal calibration routine and reported a pass, and the levelling bubble sits correctly. Before any weighing is accepted for calibrator preparation, what further check should the technologist perform?

Accepted Answer

Weigh a certified mass standard and log it — An internal routine adjusts the balance against a mass built into the instrument, so it confirms the balance is self-consistent without proving that it agrees with the outside world. Weighing a certified mass standard, traceable to a national standard, is what demonstrates accuracy, and the reading with its acceptance limits belongs in the balance log. For calibrator preparation, where a weighing error propagates into every patient result on that curve, this external check is expected before the weighings are used.

Question 2

A monthly optics cleaning on a chemistry analyser was missed because the technologist assigned to it was on leave. The instrument is running normally and today's controls sit within their limits. What should the laboratory do?

Accepted Answer

Perform the cleaning now and log the lapse — A missed upkeep task is a non-conformance whether or not the controls happened to pass; acceptable controls show the analyser was performing at the moment they were run, not that scheduled upkeep was unnecessary. The overdue task is carried out at the first opportunity, and both the delay and its reason are recorded so the gap stays visible during review and trending.

Question 3

Part-way through a batch, an immunoassay analyser halts with a probe-obstruction alarm. The technologist clears the blockage using the manufacturer's fault guide and the instrument restarts with no further alarms. Twelve patient specimens were on board when it stopped. What must happen before those results are released?

Accepted Answer

Run quality control on the affected assays — Clearing a blockage restores the instrument mechanically but says nothing about whether the specimens on board were aspirated correctly while it was failing. Running controls on the affected assays and confirming they are acceptable is what re-establishes confidence in the run, and it happens before any of those twelve results leave the laboratory. Should the controls fail, the on-board specimens are repeated rather than reported.

Question 4

A chemistry analyser returns a photometric lamp error. The technologist works through every step of the manufacturer's fault-finding sequence, including fitting a new lamp, and the same error reappears within the hour. Ten stat specimens are waiting. What is the appropriate next action?

Accepted Answer

Call the service engineer and reroute the work — Once the manufacturer's sequence has been worked through, including replacing the suspect part, and the fault returns, the problem sits beyond bench troubleshooting and belongs with technical service. Stat work cannot wait for that visit, so the specimens move to a backup analyser or a referral site while the service call and the actions already taken are logged.

Question 5

A technologist is photographing a urine sediment field to send for consultation. Down the eyepieces the field looks correct, but the captured file is yellow-tinged and the background brightness falls away towards one edge. Which adjustment should be made before recapturing?

Accepted Answer

Set white balance and re-establish Köhler — The eyepieces and the camera do not see the same thing: the sensor renders colour according to its white-balance setting, and a background that fades towards one edge comes from illumination that is not correctly aligned. Setting white balance on a clear, empty part of the field and re-establishing Köhler illumination corrects both faults at their source, and both should be confirmed at the start of any capture session.

Question 6

A technologist captures several images of an abnormal urine sediment and saves them to the desktop of a shared microscope workstation, naming each file with the patient's surname so a colleague can review them later that week. Which part of this practice breaches laboratory policy?

Accepted Answer

Local storage under an identifying file name — Saving patient images to the desktop of a shared workstation places identifiable information outside the systems that control access, retention and disposal, and a file name carrying a surname makes the patient identifiable to anyone who walks past. Bench images are patient records: they belong in the archive route named in the SOP, linked to the patient by accession identifier rather than by name.

Equipment and Resources

Keeping instruments in a state you can trust

First response when an instrument fails mid-run

Producing and safeguarding digital images