URINE
Timing: The first morning urine is preferred as it typically has the highest concentration of hCG, though a sample can be collected at any time of day. Perform the test immediately after collection for best results.
Storage: If testing is delayed, the specimen may be stored at 2-8°C (36-46°F) for up to 48 hours. For prolonged storage, specimens should be frozen at below -20°C (-4°F). Frozen specimens must be thawed and mixed well before testing.
Physical Quality: The urine should ideally be clear. Specimens with visible precipitates should be allowed to settle, centrifuged, or filtered to obtain a clear supernatant for testing. Color and pH of the urine generally do not affect the test results.
qPCR
(RML)
Non-Interfering Substances: Common interfering substances such as LH (luteinizing hormone, up to 300 mIU/mL), FSH (follicle stimulating hormone, up to 1,000 mIU/mL), TSH (thyroid stimulating hormone, up to 1,000 µIU/mL), chyluria, proteinuria, hematuria, and bilirubinuria typically do not affect test results.
Interfering Factors/Conditions:
External hCG administration: Injections or oral administration of hCG (e.g., for fertility treatments) can cause false positive results.
Medical conditions: Certain medical conditions other than pregnancy, such as some trophoblastic diseases and non-trophoblastic cancers (e.g., testicular, prostate, breast, or lung cancer), can cause elevated hCG levels.
Hook effect: Very high concentrations of hCG (e.g., >500,000 mIU/mL) may rarely cause a false negative result due to the “”hook effect””; if suspected, the sample should be diluted and retested.
Improper procedure/Expired test: Using an expired test, incorrect procedural technique, or insufficient specimen volume can lead to invalid or erroneous results.
Read Instructions Carefully: The collector must read the specific manufacturer’s instructions in the package insert before use.
Handle with Care: The test cassette should not be touched on the membrane, and contact with the result window should be avoided to prevent contamination.
Single Use: Each cassette is a single-use disposable device.
Aspirate Correct Volume: Use the provided dropper and add the exact number of drops (usually 3-4 drops, approximately 120 µL) into the specimen well (S), avoiding air bubbles.
Use at Room Temperature: Ensure the test cassette and the specimen are at room temperature (15-30°C or 59-86°F) before testing.
Timing is Crucial: Start a timer immediately after adding the specimen to the well. Read results at the specified time (typically 3-5 minutes), but do not interpret results after 10 minutes as the results may no longer be valid.
Safety and Disposal: Urine specimens should be handled with care as potentially infectious. The used test cassette and collection container should be discarded according to local biohazard waste regulations.
Invalid Test: If the control line (C) does not appear, the test is invalid, and the procedure should be repeated with a new test device.
Confirmation: A confirmed diagnosis of pregnancy should be made by a physician after evaluating all clinical and laboratory findings.
