8.3 Non-Blood Specimen Processing
Key Takeaways
- Match urine collection type (random, clean-catch, 24-hour) to the order; measure and record 24-hour total volume and verify correct preservatives
- Handle body fluids with sterile technique when culture is ordered; label every container and maintain chain of identity across multiple tubes
- Treat CSF as urgent—prioritize delivery, department routing, and communication; do not delay for batch convenience
- Use correct stool and sputum containers; reject leaking specimens that risk exposure and compromise integrity
8.3 Non-Blood Specimen Processing
Quick Answer: Process non-blood specimens by matching container and collection type to the order, protecting identity and sterility, measuring 24-hour urine total volume with the correct preservative, treating CSF as STAT/urgent, using proper stool and sputum containers, and rejecting leaking containers that endanger staff and invalidate samples.
Blood tubes dominate phlebotomy training, but Domain II expects equal competence with urine, CSF, other body fluids, stool, and sputum. These specimens are often irreplaceable (OR fluids, CSF) or time-critical (culture, cell counts). The MLA’s job is correct receipt, labeling verification, aliquoting when allowed, prioritization, and safe rejection—not diagnostic interpretation.
Urine Processing
Random urine
- Common for routine urinalysis, many drug screens (non-forensic), and some chemistry tests.
- Transfer promptly from collection cup to UA tube or analyzer cup per SOP to limit bacterial overgrowth and analyte change.
- Mix gently before pouring so sediment is representative for microscopic exam.
- Note collection time when clinically relevant (e.g., post-dose drug levels).
Clean-catch midstream
- Intended to reduce periurethral contamination for urine culture and often for routine UA when infection is suspected.
- Requires a sterile container or culture preservative tube.
- At processing: do not open longer than necessary; do not dip non-sterile instruments into a culture specimen before plating/setup.
- If the cup is grossly contaminated on the exterior, clean per policy without compromising the lid seal; leaking culture cups are rejection candidates.
24-hour (timed) urine
Timed collections support quantitative chemistry (protein, creatinine clearance inputs, electrolytes, cortisol, heavy metals—test-specific).
| MLA responsibility | Detail |
|---|---|
| Preservative check | Acid, base, or plain jug as ordered—wrong preservative may invalidate the study |
| Completeness | All voids in the period; missing voids → reject/recollect timed study |
| Total volume | Mix thoroughly, measure entire volume, record in LIS (mL or L per policy) |
| Aliquots | Pour well-mixed aliquots for each ordered test; label with volume and collection interval |
| Safety | Some acidified jugs are corrosive—PPE, spill response, never mouth-pipette |
Critical: Calculations use total volume. Estimating from a partial jug or “eyeballing” liters destroys quantitative accuracy. If the patient discarded urine or used the wrong jug, process as a failed collection per policy.
Urine culture preservative tubes
Boric acid or other transport tubes stabilize colony counts when delay is expected. Do not use an old non-sterile cup sitting for hours when policy requires a preservative tube—flag and follow micro rejection rules.
Body Fluids (Pleural, Peritoneal, Synovial, Drain Fluids)
Body fluids may be ordered for cell count, differential, chemistry, crystals, and culture—often from the same procedure with multiple tubes.
Labeling
- Each tube/syringe labeled at the bedside with two identifiers, source (e.g., left pleural), date/time, and collector.
- Multiple tubes: keep order of draw/priority as clinical staff indicate (often culture first to reduce contamination).
- Never relabel by guessing which unlabeled syringe is “the culture.”
Sterile handling
- Culture portions: sterile containers, minimal opening, prompt delivery to microbiology.
- Do not decant culture fluid through non-sterile chemistry cups first if that contaminates the culture aliquot—follow the lab’s split order.
- Chemistry/cell count tubes may be anticoagulant-specific (e.g., EDTA for cell counts—confirm local policy).
Clotting and delay
Some fluids clot quickly; delayed processing ruins cell counts. Prioritize and communicate with hematology/micro as soon as the specimen arrives.
CSF: Urgency Is Non-Negotiable
Cerebrospinal fluid is obtained by lumbar puncture or shunt tap—invasive and often not easily repeated.
| Priority action | Why |
|---|---|
| Hand-carry or expedite transport | Cell counts and glucose change with delay; organisms may die |
| Notify receiving departments | Micro, hematology, chemistry may all share limited volume |
| Protect from extreme temperatures | Follow lab policy |
| Do not batch with routine urines | CSF is not a “when you get to it” specimen |
| Volume triage | If QNS for all tests, escalate—pathologist/supervisor sets priority |
Typical tube numbering (facility-specific; do not invent):
- Tube 1 often chemistry or least contaminated depending on protocol
- Intermediate tubes for micro/heme
- Last tube sometimes preferred for cell count to reduce traumatic-tap blood
Know your laboratory’s CSF tube allocation chart. The MLA ensures tubes go to the correct benches promptly and that labels stay with the fluid that was drawn.
If a CSF leaks in transport, treat as a major problem: exposure risk, volume loss, possible rejection—notify immediately.
Stool Specimens
| Order type | Container / notes |
|---|---|
| Occult blood (FOBT/FIT) | Manufacturer card or device; correct patient prep when required; do not use expired cards |
| Culture | Enteric pathogen transport vial as specified; do not use random diaper smear in a non-sterile open cup when a Cary-Blair-type medium is required |
| C. difficile | Soft/liquid stool per policy; formed stool often rejected for toxin/PCR algorithms |
| O&P | Vials with fixative (e.g., formalin/PVA systems) filled to line; ratio matters |
| Fecal fat / other timed studies | Entire collection instructions—follow send-out manual |
Reject stool cups that are leaking, unlabeled, or wrong media for the test. Do not transfer leaking stool with bare hands; use PPE and consider recollection in a proper sealed container.
Sputum
- Morning deep-cough specimens preferred for many respiratory studies; saliva-only specimens may be rejected by micro quality screens.
- Sterile screw-cap containers; tight seal.
- Process promptly for culture; refrigeration rules vary by test—follow SOP.
- AFB or special studies may need specific volume and paperwork—check orders before discarding “extra” specimen.
Rejection of Leaking Containers
Leaking urine jugs, stool cups, fluid syringes without secure caps, and cracked CSF tubes are biohazard and quality failures.
| Why reject / problem-solve | Rationale |
|---|---|
| Staff exposure | Standard Precautions; unknown pathogens |
| Label loss or soak-off | Identity risk |
| Cross-contamination of bags/racks | Other patients’ specimens |
| Volume loss / drying | Invalid quantitative or culture results |
| Regulatory/safety | Transport rules violated |
Actions:
- Do not continue pouring from a leaking primary into clean tubes as if nothing happened without supervisor guidance.
- Contain the leak with absorbent pads; PPE on.
- Document; notify collecting unit for recollection when the specimen is replaceable.
- For irreplaceable fluids, escalate immediately—leadership may salvage remaining sealed portions with documentation.
- Disinfect contaminated surfaces and transport bags.
Exterior fecal or urine soil on a closed, intact, properly labeled container may be cleaned and accepted per policy—leak through the seal is different from a dirty outside.
Practical Receipt Checklist (Non-Blood)
- Match order ↔ container type ↔ source.
- Verify two identifiers and collection data.
- Inspect for leaks, cracks, and adequacy of volume.
- Apply priority (CSF/STAT fluids first).
- Measure 24-hour urine total volume after mixing.
- Aliquot only with labeled secondaries and clean technique.
- Route to micro/heme/chem with minimal delay.
- Reject and communicate clearly when containers fail safety or quality rules.
Key Takeaways
- Urine type and preservative must match the order; 24-hour total volume is measured and recorded after thorough mixing.
- Body fluids need source-specific labels and sterile handling for culture.
- CSF is urgent—expedite, triage volume, never batch as routine.
- Stool and sputum require correct devices/media; quality screens reject saliva-only or wrong-consistency specimens when policy says so.
- Leaking containers are safety and integrity problems—contain, document, recollect or escalate.
A 24-hour urine for protein arrives. What must the MLA do before creating chemistry aliquots?
CSF tubes arrive from the ED for culture, cell count, and chemistry. What is the most appropriate MLA priority?
A stool culture order is received in a leaking, non-sterile food container. What should the MLA do?
Why is a clean-catch midstream urine preferred for routine bacterial culture?