Specimen Collection

Most microbiology failures begin before the specimen reaches the bench, so technologists are expected to give patients and collectors specific, usable direction. That means naming the correct container and preservative, the anatomical site, the volume the method actually needs, and the window within which the specimen must arrive. It also means explaining why an instruction exists — that a first-morning deep-cough sputum outperforms saliva pooled across a day, or that swabbing dry slough says nothing about the infected tissue beneath it. One clear set of instructions prevents a repeat collection, a delayed diagnosis and a second visit for the patient.

Not every request that arrives is a question the laboratory can answer. Technologists are expected to recognise orders that will generate a result without clinical meaning: anaerobic culture on a voided urine, a routine enteric stool culture on diarrhoea that began well into a hospital stay, daily repeat cultures on a stable patient, or a specimen sent looking for an organism the requested method cannot recover. The response is not a silent refusal. It is a call to the requester that explains the limitation and offers the test that answers the real clinical question, with the conversation recorded against the specimen.

Before anything is accessioned, the container and the requisition have to tell the same story. The technologist confirms that names, unique identifiers, collection date and time, anatomical site and the number of containers match on both, and that the label sits on the container rather than on the bag around it. In microbiology a site mismatch is not clerical trivia: the stated source decides which media are inoculated, which atmosphere the plates go into, and how any normal flora recovered will be interpreted. Where the two disagree, the collector resolves it, not the laboratory.

Integrity assessment asks whether the material in front of you can still support a defensible result. The technologist checks volume against what the method needs, container and preservative type, transport temperature and elapsed time, leakage, gross contamination, and for respiratory specimens the cytological screen for squamous contamination. Some faults are fatal: a swab that has dried out, or a culture specimen frozen in transit. Others degrade the result without destroying it — a sterile fluid left overnight in a ward refrigerator is still processed when fastidious organisms are suspected, because a positive result remains informative, but the delay is reported alongside it. Others are recorded as limitations and reported beside the result so the clinician can weigh how much confidence it deserves.

Some specimens are evidence as well as clinical material. Forensic collections, workplace substance testing and specimens tied to a coroner's investigation travel under chain of custody: every transfer signed and timed, seals intact, containers uniquely identified, and storage documented from collection through to disposal. The technologist verifies the seal and the paperwork on arrival, signs for the transfer, restricts access to the specimen, and records any irregularity rather than quietly putting it right. A broken seal is reported to the submitting authority and documented; it is never resealed, because a repaired seal destroys the very assurance the seal was there to give.

Accessioning is where a specimen becomes a record that can be traced. The technologist enters patient identifiers, ordering clinician, collection date and time, receipt time, anatomical source, tests requested and any special instruction, then applies the accession label. Source coding matters more in microbiology than in most disciplines, because the entered site drives media selection, incubation atmosphere, work-up rules, reporting comments and turnaround targets. A vague entry such as wound, other quietly weakens all of them. Rejections, limitations and conversations with the ward belong in the same record, not in a note on the bench.

Delivery priority is a judgement about what deteriorates fastest and what changes management soonest. Cerebrospinal fluid, sterile body fluids, tissue from theatre and specimens sought for fastidious organisms such as Neisseria gonorrhoeae move immediately, at the temperature that keeps the organism alive. Preserved material — urine in boric acid, stool in fixative, screening swabs in transport medium — tolerates the scheduled courier run. Technologists are expected to know which specimens must never be chilled, which must be, and when the right answer is to call for a dedicated run rather than wait for the next one.

The same reasoning that ranks transport ranks the bench queue. Irreplaceable sterile-site material is set up first — joint and pleural aspirates, tissue from theatre, cerebrospinal fluid — followed by specimens whose yield falls with every hour of delay, with preserved urines and screening swabs last. There is an order within a single specimen too: anaerobic media are inoculated before aerobic ones from a closed aspirate, and with a scarce volume the media are inoculated before smears, since a culture can be repeated from a plate but never from a slide. Prioritising also means protecting sterile specimens from cross-contamination during a crowded setup.

Discrepancy detection is the habit of noticing that something about a specimen does not fit. Two blood culture bottles arriving when the requisition records four. A collection time later than the receipt time. A urine labelled midstream that shows heavy mixed growth. A second container with no label at all. The technologist traces the problem back to the collector rather than reconstructing the missing detail from a chart, records both the finding and how it was resolved, and escalates a repeating pattern from one collection area into the quality system so the cause is fixed rather than absorbed.

The plate shown was inoculated from a voided urine submitted by a family practice, and two clearly different colony types have grown in substantial numbers. What does this growth pattern most likely say about how the specimen was obtained?

AThe container held boric acid preservativeBThe loop delivered too large a volumeCPerineal flora entered during voidingDThe sample was chilled before plating

One aerobic blood culture bottle arrives on its own. The requisition records two sets drawn from separate sites, and the bottle carries no draw site and no draw time. What is the technologist's first step?

ALoad the bottle and report as one setBCancel the request and ask for a redrawCEnter the missing details from the chartDContact the collector to trace the set

Identification is the one check with no acceptable failure rate. At collection the patient is identified actively using two independent identifiers verified against the requisition and the wristband, and the container is labelled at the bedside before the collector steps away. The same two identifiers are matched again at accessioning. Patients who cannot confirm their own details — infants, unconscious trauma arrivals, people with dementia or without a shared language — are identified through the wristband, a temporary unique identifier or an accompanying caregiver. Unlabelled specimens are never labelled retrospectively by laboratory staff, however inconvenient a recollection may be.