add thimerosal (0.001%) or sodium azide
(0.01%) to the specimen and store at 2–8°C up to 72 hours.
Do not use grossly contaminated specimens and if the
specimen is cloudy or bloody, centrifuge at 1000 rpm
(125 g) for one minute and use clear supernatant for
Specimens collected over a 24-hours period should be
pooled in a clean detergent free container and refrigerated
at 2–8°C. Thimerosal (0.001%) or sodium azide (0.01%) are
recommended as urine preservatives.
Material Provided with the Kit
Anti-beta human chorionic gonadotropic antibody (mouse
monoclonal), hCG latex antigen.
Glass slide with three reaction circles, pipettes for dispensing
urine specimen, mixing sticks, rubber teats.
Positive and negative urine controls, isotonic saline, a high
intensity direct light source, stopwatch.
414 Concise Book of Medical Laboratory Technology: Methods and Interpretations Test Procedure
Bring all reagents and samples to room temperature before
1. Place one drop of urine (specimen or control) on the
glass slide using a disposable pipette provided with
the kit. Deliver the drop vertically.
2. Add one drop of anti-beta hCG antibody to the drop
of urine on the slide. Deliver the drop vertically.
3. Using a mixing stick, mix the antibody and urine
uniformly over the entire circle for 30 seconds.
4. Add one drop of latex reagent to the mixture. Mix
uniformly over the entire circle. Do not let the dropper
tip touch the liquid on the slide.
5. Immediately start a stopwatch. Rock the slide gently
back and forth, observing for agglutination macroscopically at 3 minutes.
1. Measure and record the total volume of patient urine
collected over a 24-hour period.
2. Using isotonic saline, prepare progressive dilutions from an aliquot of collected urine specimen.
3. Perform the qualitative test procedure using each
Agglutination is a negative test result indicating the
absence of detectable levels of hCG.
No agglutination is a positive test result indicating the
presence of detectable levels of hCG.
No agglutination in the highest urine dilution corresponds
to the amount of hCG/mL. To calculate the concentration
of hCG in the specimen, use the following formula, hCG =
where, S = sensitivity of the test, i.e. 0.3 IU/mL
D = highest dilution of urine showing no agglutination.
For determining 24 hour hCG concentration, use the
following formula, hCG 24 hours = S × D × V where, V =
volume of 24 hours urine specimen.
1. Patient specimens, in pathological conditions such as
a hydatidiform mole or choriocarcinoma or testicular
tumor, may contain hCG and produce a positive test
result not necessarily indicating a pregnancy.
2. Values of hCG greater than 250 IU/mL, 110 days after
LMP, suggest the presence of a pathological condition
such as a hydatidiform mole or choriocarcinoma.
3. Use only urine as test specimen. Do not use serum.
4. It is recommended that results of the tests should be
correlated with clinical findings to arrive at the final
(Foresight from Tulip Group of Companies)
Direct Latex Agglutination Method
Human chorionic gonadotropin (hCG), a hormone
produced by viable placental tissue during pregnancy,
is excreted in urine approximately 20 days after the last
menstrual period. The levels of hCG rise rapidly reaching
peak levels after 60 to 80 days and then the hCG levels fall
suddenly and eventually plateau out.
The hCG molecule consists of two combined dissimilar
subunits namely, alpha and beta. The alpha subunit is
practically identical to the alpha subunit of luteinizing
hormone (LH), follicle-stimulating hormone (FSH) and
thyroid-stimulating hormone (TSH). The beta subunit
of hCG, by virtue of its unique amino acid sequence and
content, confers biological and immunological specificity
The appearance of hCG in urine soon after conception
and its rapid rise in concentration makes it an ideal marker
for detection and confirmation of pregnancy. However,
elevated hCG levels are frequently associated with
trophoblastic and non-trophoblastic neoplasms, these
conditions should be considered before a diagnosis of
pregnancy can be made. Foresight slide test for pregnancy
employs monoclonal antibodies specific to the beta
1. Foresight latex reagent: A uniform suspension of
polystyrene latex particles coated with beta hCG
specific mouse monoclonal antibodies.
2. Positive control, reactive with the Foresight latex
3. Negative control, non-reactive with the Foresight latex
Each batch of reagent undergoes rigorous quality
control at various stages of manufacture for its specificity,
Store the reagent at 2–8°C. Do not freeze.
The shelf-life of reagent is as per the expiry date
mentioned on the reagent vial label.
Foresight slide test for pregnancy utilizes the principle
of direct latex agglutination. The urine specimen to be
tested is mixed with the latex reagent coated with beta
hCG specific mouse monoclonal antibodies and mixture
is allowed to react. When the urine specimen is from a
pregnant woman and contains at least 0.2 lU/mL of hCG,
it reacts with latex reagent coated with anti-beta hCG
When the urine specimen is from a non-pregnant
woman and does not contain hCG it does not react with the
latex reagent coated with beta hCG specific monoclonal
antibodies and hence no agglutination is observed.
1. In vitro diagnostic reagent for laboratory and
professional use only. Not for medicinal use.
2. Reagent contains 0.1% sodium azide as preservative.
Avoid contact with skin and mucosa. On disposal flush
with large quantities of water.
is recommended that the performance of the reagent
should be verified by testing with known positive and
4. Do not interchange vial droppers/caps.
5. Shake the latex reagent vial well before use to disperse
the latex particles uniformly and improve test
6. Only a clean and dry glass slide must be used. Clean
the slide with distilled water and wipe dry. Do not use
detergents, soaps, or organic solvents to clean the slide.
7. Accessories provided with the kit only must be used
Specimen Collection and Preparation
Though random urine specimens can be used, first
morning urine specimen is preferable. Specimens should
be collected in clean glass or plastic containers free of
detergents. Specimens should be tested immediately
preferably within 12 hours of collection. Should a delay
in testing occur, add thimerosal (0.001%) or sodium azide
(0.01%) to the specimen and store at 2–8°C up to 72 hours.
Do not use grossly contaminated specimens and if the
specimen is cloudy or bloody, centrifuge at 1000 rpm
(125 g) for one minute and use clear supernatant for
Specimens collected over a 24-hour period should be
pooled in a clean detergent free container and refrigerated
at 2–8°C. Thimerosal (0.001%) or sodium azide (0.01%) are
recommended as urine preservatives.
Material Provided with the Kit
Latex reagent coated with beta hCG-specific mouse
monoclonal antibodies, Positive control, negative
control, glass slide with three reaction circles, Pipettes for
dispensing urine specimen, mixing sticks, rubber teats.
Isotonic saline, A high intensity direct light source,
Bring reagent and urine specimen to room temperature
1. Place one drop of urine (specimen or control) on
the glass slide using the disposable pipette provided
with the kit. Deliver the drop by holding the dropper
2. Even for dispensing controls, the use of sample
dispensing pipettes is recommended.
3. Add one drop of latex reagent to the specimen. Mix
uniformly over the entire circle. Do not let the dropper
tip touch the liquid on the slide.
4. Immediately start the stopwatch. Rock the slide
gently back and forth, observing for agglutination
Measure and record the total volume of patient’s urine
collected over a 24-hour period. Using isotonic saline,
prepare progressive dilutions from an aliquot of collected
urine specimen (1:2, 1:4, 1:8 and so on). Perform the
qualitative test procedure using each dilution as specimen.
Interpretation of Test Results
Agglutination is a positive test result and indicates
presence of detectable levels of hCG in the specimen
indicating pregnancy. No agglutination is a negative test
result and indicates absence of detectable levels of hCG.
To calculate the concentration of hCG in the specimen,
where, S = Sensitivity of the test, i.e. 0.2 IU/mL
D = Highest dilution of urine under test showing
1. Patient specimen, in pathological conditions such as
hydatidiform mole or choriocarcinoma, may contain
hCG and produce a positive test result not necessarily
2. During the first trimester of a normal pregnancy, hCG
levels as high as 160–180 lU/mL may be obtained.
3. Values of hCG greater than 250 lU/mL, 110 days
after LMP, may suggest the presence of pathological
condition such as hydatidiform mole or choriocarcinoma.
4. Foresight is designed to detect hCG levels attained
during the course of a normal pregnancy. As in case
of similar pregnancy tests, prozoning may occur with
5. Use only urine as test specimen. Do not use serum.
6. It is recommended that results of the tests should be
correlated with clinical findings to arrive at the final
7. If the result is negative and pregnancy is still suspected,
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