20/10/2025
LABORATORY SPECIMEN SUBMISSION
Submitting the correct amount or volume of a specimen for laboratory testing is crucial for ensuring accurate and reliable results. Too little might mean the lab can't perform all necessary tests, while too much can sometimes be unnecessary or make handling difficult.
GENERAL GUIDE ON APPROPRIATE SPECIMEN AMOUNTS, DIFFERENTIATING BETWEEN ROUTINE AND MORE COMPLEX TESTS.
Always refer to specific instructions from your healthcare provider or the laboratory, as requirements can vary!
1. STOOL (F***S) SPECIMENS
Stool samples are vital for diagnosing digestive issues, infections, and other conditions.
FOR ROUTINE EXAMINATION (e.g., Occult Blood, Ova & Parasites, Culture):
✓ AMOUNT: Typically, a walnut-sized portion (about 2-5 grams) is sufficient. If using a collection kit, there will often be a designated fill line or scoop.
✓ METHOD: Collect from different parts of the stool (top, middle, and end) to get a representative sample. Avoid mixing with urine or toilet water.
✓WHY: This amount provides enough material for microscopic examination, chemical tests, and culture without being excessive.
FOR COMPLEX/SPECIALIZED TESTS (e.g., Quantitative F***l Fat, Elastase):
✓ AMOUNT: These tests often require larger, sometimes timed, collections. For example, a 24- or 72-hour f***l fat test requires all stool passed during that period.
✓ METHOD: You'll be provided with special containers and detailed instructions for collecting every bowel movement over the specified time.
✓WHY: These tests measure total output or specific components over time, requiring a comprehensive collection to be accurate.
2. URINE SPECIMENS
Urine samples are incredibly versatile for detecting kidney disease, UTIs, metabolic disorders, and more.
FOR ROUTINE URINALYSIS (UA) & Culture:
✓ VOLUME: 30-60 mL (about 2-4 tablespoons) is generally ideal. Some labs can work with less (e.g., 10-20 mL) if needed.
✓ METHOD: A "mid-stream clean catch" is usually required to avoid contamination. Collect the urine into a sterile container.
✓ WHY: This volume allows for chemical strip testing, microscopic examination of sediment, and microbial culture if indicated.
FOR COMPLEX/SPECIALIZED TESTS:
a) 24-HOUR URINE COLLECTION (e.g., Creatinine Clearance, Protein, Cortisol):
✓ VOLUME: This requires collecting all urine passed over a full 24-hour period. You will be given a large container (typically 2-4 liters capacity), sometimes containing a preservative.
✓ METHOD: You start by emptying your bladder and discarding that first urine. Then, for the next 24 hours, you collect every drop of urine passed into the provided container. At the exact 24-hour mark, you empty your bladder one last time into the container.
✓ WHY: These tests measure how much of a substance your kidneys process or excrete over an entire day, requiring a complete collection for accurate calculations and diagnoses.
b) FIRST MORNING URINE (e.g., for specific protein markers, pregnancy tests):
✓ VOLUME: Usually 30-60 mL.
✓METHOD: Collect the very first urine you pass upon waking.
✓ WHY: This urine is typically more concentrated, making it ideal for detecting substances that might be diluted later in the day.
c) POST-PRANDIAL URINE (e.g., Glucose):
✓ VOLUME: Typically 30-60 mL.
✓ METHOD: Collected a specific time after a meal (e.g., 2 hours).
✓ WHY: Used to assess how the body handles substances like glucose after food intake.
KEY TAKEAWAYS FOR ALL SPECIMENS
a) Read Instructions Carefully: Always prioritize the specific instructions given by your doctor or the lab.
b) Use Provided Containers: Labs provide sterile, appropriate containers for a reason.
c) Label Clearly: Ensure your name, date, and time of collection are clearly written on the container.
d) Store Correctly: Follow guidance on refrigeration or special handling to maintain specimen integrity.
e) Ask Questions: If anything is unclear, don't hesitate to ask your healthcare provider or the laboratory staff for clarification.
By taking a moment to understand and follow collection guidelines, you play a vital role in ensuring the accuracy of your diagnostic tests and supporting effective healthcare!
Douglas J Moyo Dickson Sandala Health Workers Connect Health Professions Council of Zambia - HPCZ Ministry of Health Zambia Dr. Mujajati Aaron
