hCG One Step Pregnancy Test Strip

hCG
One Step Pregnancy Test Strip (Urine)

A rapid, one step test for the qualitative detection of human chorionic gonadotropin (hCG) in urine.
For professional in vitro diagnostic use only.

 

INTENDED USE

The hCG One Step Pregnancy Test Strip (Urine) is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin in urine to aid in the early detection of pregnancy.

 

SUMMARY

Human chorionic gonadotropin is a glycoprotein hormone produced by the developing placenta shortly after fertilization. In normal pregnancy hCG can be detected in both urine and serum as early as 7 to 10 days after conception.1,2,3,4 hCG levels continue to rise very rapidly, frequently exceeding 100 mlU/mL by the first missed menstrual period2,3,4 and peaking in the 100,000-200,000 mlU/mL range about 10-12 weeks into pregnancy. The appearance of hCG in both urine and serum soon after conception, and its subsequent rapid rise in concentration during early gestational growth, make it an excellent marker for the early detection of pregnancy.

The hCG One Step Pregnancy Test Strip (Urine) is a rapid test that qualitatively detects the presences of hCG in urine specimen at the sensitivity of 25 mlU/mL. The test utilizes a combination of monoclonal and polyclonal antibodies to selectively detect elevated levels of hCG in urine. At the level of claimed sensitivity, the hCG One Step Pregnancy Test Strip (Urine) shows no cross-reactivity interference from the structurally related glycoprotein hormones hFSH, hLH and hTSH at high physiological levels.

 

PRINCIPLE

The hCG One Step Pregnancy Test Strip (Urine) is a rapid chromatographic immunoassay for the qualitative detection of human chorionic gonadotropin in urine to aid in the early detection of pregnancy. The test utilizes a combination of antibodies including a monoclonal hCG antibody to selectively detect elevated levels of hCG. The assay is conducted by immersing the test strip in a urine specimen and observing the formation of colored lines. The specimen migrates via capillary action along the membrane to react with the colored conjugate.

Positive specimens react with the specific antibody-hCG-colored conjugate to form a colored line at the test line region of the membrane. Absence of this colored line suggests a negative result. To serve as a procedural control, a colored line will always appear in the control line region indicating that proper volume of specimen has been added and membrane wicking has occurred.

 

REAGENTS

The test strip contains anti-hCG particles and anti-hCG coated on the membrane.

 

PRECAUTIONS

• For professional in vitro diagnostic use only. Do not use after the expiration date.

• The test strip should remain in the sealed pouch until use.

• All specimens should be considered potentially hazardous and handled in the same manner as an infectious agent.

• The test strip should be discarded in a proper biohazard container after testing.

 

STORAGE AND STABILITY

The kit can be stored at room temperature or refrigerated (2-30oC). The test strip is stable through the expiration date printed on the sealed pouch. The test strip must remain in the sealed pouch until use. DO NOT FREEZE. Do not use beyond the expiration date.

 

SPECIMEN COLLECTION AND PREPARATION

Urine Assay

A urine specimen must be collected in a clean and dry container. A first morning urine specimen is preferred since it generally contains the highest concentration of hCG; however, urine specimens collected at any time of the day may be used. Urine specimens exhibiting visible precipitates should be centrifuged, filtered, or allowed to settle to obtain a clear specimen for testing.

Specimen Storage
Urine specimens may be stored at 2-8oC for up to 48 hours prior to testing. For prolonged storage, specimens may be frozen and stored below-20°C. Frozen specimens should be thawed and mixed before testing.

 

MATERIALS

Materials Provided

• Test strips

• Package insert

Materials Required But Not Provided

• Specimen collection container

• Timer

 

DIRECTIONS FOR USE

Allow the test strip, urine specimen and/or controls to equilibrate to room temperature (15-30 °C) prior to testing.

1. Bring the pouch to room temperature before opening it. Remove the test strip from the sealed pouch and use it as soon as possible.

2. With arrows pointing toward the urine specimen, immerse the test strip vertically in the urine specimen for at least 10-15 seconds. Do not pass the maximum line (MAX) on the test strip when immersing the strip. See the illustration below.

3. Place the test strip on a non-absorbent flat surface, start the timer and wait for the red line(s) to appear. The result should be read at 3 minutes.

Note: A low hCG concentration might result in a weak line appearing in the test region (T) after an extended period of time; therefore, do not interpret the result after 10 minutes.

 

INTERPRETATION OF RESULTS

POSITIVE:* Two distinct red lines appear. One line should be in the control region (C) and another line should be in the test region (T).

* NOTE: The intensity of the red color in the test line region (T) will vary depending on the concentration of hCG present in the specimen. Therefore, any shade of red in the test region (T) should be considered positive.

NEGATIVE: One red line appears in the control region (C). No apparent red or pink line appears in the test region (T).

INVALID: Control line fails to appear. Insufficient specimen volume or incorrect procedural techniques are the most likely reasons for control line failure. Review the procedure and repeat the test with a new test strip, if the problem persists, discontinues using the test kit immediately and contact your local distributor.

 

QUALITY CONTROL

A procedural control is included in the test. A red line appearing in the control region (C) is the internal procedural control. It confirms sufficient specimen volume and correct procedural technique.

It is recommended that a positive hCG control (containing 25-250 mlU/mL hCG) and a negative hCG control (containing “0” mIU/mL hCG) be evaluated to verify prop test performance when a new shipment of test devices a received.

 

LIMITATIONS

1. The hCG One Step Pregnancy Test Strip (Urine) is a qualitative test, therefore, neither the quantitative value nor the rate of increase in hCG can be determined by this test.

2. Very dilute urine specimens, as indicated by a low specific gravity, may not contain representative levels of hCG. If pregnancy is still suspected, a first morning urine specimen should be collected 48 hours later and tested.

3. False negative results may occur when the levels of hCG are below the sensitivity level of the test. When pregnancy is still suspected, a first morning urine specimen should be collected 48 hours later and tested.

4. Very low levels of hCG (less than 50 mlU/mL) are present in urine specimen shortly after implantation. However, because a significant number of first trimester pregnancies terminate for natural reasons,5 a test result that is weakly positive should be confirmed by retesting with a first morning urine specimen collected 48 hours later.

5. A number of conditions other than pregnancy, including trophoblastic disease and certain non-trophoblastic neoplasms including testicular tumors, prostate cancer, breast cancer, and lung cancer, cause elevated levels of hCG6,7 Therefore, the presence of hCG in urine should not be used to diagnose pregnancy unless these conditions have been ruled out.

6. This test provides a presumptive, diagnosis for pregnancy. A confirmed pregnancy diagnosis should only be made by a physician after all clinical and laboratory findings have been evaluated.

 

EXPECTED VALUES

Negative results are expected in healthy non-pregnant women and healthy men. Healthy pregnant women have hCG present in their urine and serum specimens. The amount of hCG will vary greatly with gestational age and between individuals.

The hCG One Step Pregnancy Test Strip (Urine) has a sensitivity of 25 mlU/mL, and is capable of detecting pregnancy as early as 1 day after the first missed menses.

 

PERFORMANCE CHARACTERISTICS

Accuracy

A multi-center clinical evaluation was conducted comparing the results obtained using the hCG One Step Pregnancy Test Strip (Urine) to another commercially available urine membrane hCG test. The study included 150 urine specimens: both assays identified 72 negative and 78 positive results. The results demonstrated >99.0% overall accuracy of the hCG Pregnancy Test Strip (Urine) when compared to the other urine membrane hCG test.

hCG Reference Method

Method Other hCG Rapid Test Total

Results

hCG Test Strip Results Positive Negative
Positive 78 0 78
Negative 0 72 72
Total Results 78 72 150

Relative Sensitivity: 100.0% (95%100%)*

Relative Specificity: 100.0% (95%100%)*

Accuracy: 100.0% (98%100%)*

* 95% Confidence Intervals

Sensitivity and Specificity
The hCG One Step Pregnancy Test Strip (Urine) detects hCG at a concentration of 25 mIU/mL or greater. The test has been standardized to the W.H.O. Third International Standard. The addition of LH (300 mIU/mL), FSH (1,000 mlU/mL), and TSH (1,000 mIU/mL) to negative (0 mlU/mL hCG) and positive (25 mIU/mL hCG) specimens showed no cross-reactivity.

Interfering Substances
The following potentially interfering substances were added to hCG negative and positive specimens.

Acetaminophen 20 mg/mL

Acetylsalicylic Acid 20 mg/mL

Ascorbic Acid 20 mg/mL

Atropine 20 mg/mL

Bilirubin 2 mg/dL

Caffeine 20 mg/mL

Gentisic Acid 20 mg/mL

Glucose 2 g/dL

Hemoglobin 1 mg/dL

None of the substances at the concentration tested interfered the assay.

 

BIBLIOGRAPHY

1. Batzer FR. Hormonal evaluation of early pregnancy, Fertil. Steril. 1980; 34(1): 1-13

2. Catt KJ, ML Dufau, JL Vaitukaitis Appearance of hCG in pregnancy plasma following the initiation of implantation of the blastocyte, J. Clin. Endocrinol. Metab
1975; 40(3): 537-540

3. Braunstein GD, J Rasor, H. Danzer, D AdIer, ME Wade Serum human chorionic gonadotropin levels throughout normal pregnancy, Am. J. Obster, Gynecol. 1976; 126(6): 678-681

4. Lenton EA, LM Neal, R Sulaiman Plasma concentration of human chorionic gonadotropin from the time of implantation until the second week of pregnancy, Fertil. Steril. 1982; 37(6): 773-778

5. Steier JA, P Bergsjo, OL Myking Human chorionic gonadotropin in maternal plasma after induced abortion, spontaneous abortion and removed ectopic pregnancy. Obstet. Gynecol. 1984; 64(3): 391-394

6. Dawood MY. BB Saxena, R Landesman Human chorionic gonadotropin and its subunits in hydatidliform mole and choriocarcinoma, Obstet. Gynecol. 1977;
50(2): 172-181

7. Braunstein GD, JL Vaitukaitis, PP Carbone, GT Ross Ectopic production of human chorionic gonadotropin by neoplasms, Ann. Intern Med. 1973; 78(1): 39-45
No. :R015231-03
Eff.Date: 0802

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