URINE
Container: A clean, dry, plastic or glass container without any preservatives.
Specimen Type: Random urine specimen; however, a first morning urine specimen is preferred as it contains the highest concentration of hCG.
Storage (after draw):
Immediate Testing: Test the specimen as soon as possible, ideally within one hour of collection.
Short-term Storage: Specimens may be stored refrigerated at 2-8°C (36-46°F) for up to 48 hours.
Long-term Storage: For prolonged storage, specimens should be frozen at or below -20°C (-4°F).
Preparation (after storage): Frozen specimens must be completely thawed and mixed well prior to testing. Avoid repeated freezing and thawing. Refrigerated specimens must be brought to room temperature before testing
qPCR
(RML)
Diluted Urine: Very dilute urine specimens (low specific gravity) may not contain representative levels of hCG, potentially leading to false-negative results.
Medications: Only medications containing hCG (some fertility drugs) are known to interfere and potentially cause false-positive results. Other common medications like pain relievers, antibiotics, and alcohol do not typically interfere.
Medical Conditions: Certain conditions other than pregnancy, such as trophoblastic disease, some non-trophoblastic neoplasms (e.g., certain cancers), menopause, and kidney problems, can cause elevated hCG levels or interfere with results.
Specimen Quality: Visibly bloody, severely turbid, or excessively contaminated urine specimens should not be used as they may lead to erroneous results.
Improper Timing: Testing too early in the pregnancy (before hCG levels are high enough) is a common cause of false-negative results.
Patient Identification: Confirm patient identification using at least two patient identifiers before collection.
Labeling: Label the collection container with the patient’s identifiers, date, and time of collection before giving it to the patient.
Procedure: Instruct the patient on proper clean-catch urine collection procedure. In a clinical setting using a test cassette, hold the dropper vertically and transfer the correct number of drops (usually 3-4 drops, or as per manufacturer instructions) to the specimen well without trapping air bubbles.
Reading Time: Read the result within the specified time frame (typically 3-10 minutes, depending on the test). Do not interpret the result after 10 minutes as a weak test line might appear due to evaporation lines or other non-specific reactions, leading to an incorrect result.
Safety: All specimens should be considered potentially hazardous/infectious agents and handled with appropriate precautions. Dispose of used test devices in a proper biohazard container.
