DIAsource ImmunoAssays S.A. - Rue du Bosquet, 2 - B-1348 Louvain-la-Neuve - Belgium
IN VITRO DIAGNOSTIC USE
DIAsource ImmunoAssays SA - Rue du Bosquet 2, B-1348 Louvain-la-Neuve, Belgium - Tel: +32 10 84 99 11 - Fax : +32 10 84 99 90
The DIAsource LH ELISA Kit
is an enzyme immunoassay for the quantitative in vitro diagnostic
measurement of the Luteinizing Hormone
Summary and Explanation
Luteinizing hormone (LH) is produced in both men and women from the anterior pituitary gland in response to luteinizing hormone-releasing
hormone (LH-RH or Gn-RH), which is released by the hypothalamus (1-3). LH, also called interstitial cell-stimulating hormone (ICSH) in
men, is a glycoprotein with a molecular weight of approximately 30.000 daltons (4). It is composed of two non covalently associated
dissimilar amino acid chains, alpha and beta (5). The alpha chain is similar to that found in human thyroid-stimulating hormone (TSH),
follicle stimulating hormone (FSH), and human chorionic gonadotropin (hCG). The difference between these hormones lie in the amino acid
composition of their beta subunits, which account for their immunological differentiation (6-8).
The basal secretion of LH in men is episodic and has the primary function of stimulating the interstitial cells (Leydig cells) to produce
testosterone. The variation in LH concentrations in women is subject to the complex ovulatory cycle of healthy menstruating women, and
depends upon a sequence of hormonal events along the gonado-hypothalamic-pituitary axis. The decrease in progesterone and estradiol
levels from the preceeding ovulation initiates each menstrual cycle (9,10). As a result of the decrease in hormone levels, the hypothalamus
increases the secretion of gonadotropin-releasing factors (GnRF), which in turn stimulates the pituitary to increase FSH production and
secretion (4). The rising FSH levels stimulate several follicles during the follicular phase, one of these will mature to contain the egg. As the
follicle develops, estradiol is secreted, slowly at first, but by day 12 or 13 of a normal cycle increasing rapidly. LH is released as a result of
this rapid estradiol rise because of direct stimulation of the pituitary and increasing GnRF and FSH levels. These events constitute the pre-
Ovulation occurs approximately 12 to 18 hours after the LH reaches a maximum level. After the egg is released, corpus luteum is formed
which secretes progesterone and estrogen - two feedback regulators of LH (3,10).
The luteal phase rapidly follows this ovulatory phase, and is characterized by high progesterone levels, a second estradiol increase, and low
LH and FSH levels (12). Low LH and FSH levels are the result of the negative feedback effects of estradiol and progesterone on the
After conception, the developing embryo produces hCG, which causes the corpus luteum to continue producing progesterone and estradiol.
The corpus luteum regresses if pregnancy does not occur, and the corresponding drop in progesterone and estradiol levels results in
menstruation. The hypothalamus initiates the menstrual cycle again as a result of these low hormone levels (12).
Patients suffering from hypogonadism show increased concentrations of serum LH. A decrease in steroid hormone production in females is
a result of immature ovaries, primary ovarian failure, polycystic ovary disease, or menopause; in these cases, LH secretion is not regulated
(10,13). A similar loss of regulatory hormones occurs in males when the testes develop abnormally or anorchia exists. High concentrations
of LH may also be found in primary testicular failure and Klinefelter syndrome, although LH levels will not necessarily be elevated if the
secretion of androgens continues. Increased concentrations of LH are also present during renal failure, cirrhosis, hyperthyroidism, and
A lack of secretion by the anterior pituitary may cause lower LH levels. As may be expected, low levels may result in infertility in both males
and females. Low levels of LH may also be due to the decreased secretion of GnRH by the hypothalamus, although the same effect may be
seen by a failure of the anterior pituitary to respond to GnRH stimulation. Low LH values may therefore indicate some dysfunction of the
pituitary or hypothalamus, but the actual source of the problem must be confirmed by other tests (10).
In the differential diagnosis of hypothalamic, pituitary, or gonadal dysfunction, assays of LH concentration are routinely performed in
conjunction with FSH assays since their roles are closely interrelated. Furthermore, the hormone levels are used to determine menopause,
pinpoint ovulation, and monitor endocrine therapy.
PRINCIPLE OF TEST
The DIAsource LH ELISA Kit is a solid phase enzyme-linked immunosorbent assay (ELISA) based on the sandwich principle.
The microtiter wells are coated with a monoclonal [mouse] antibody directed towards a unique antigenic site on a LH molecule. An aliquot of
patient sample containing endogenous LH is incubated in the coated well with enzyme conjugate, which is an anti-LH monoclonal antibody
conjugated with horseradish peroxidase. After incubation the unbound conjugate is washed off.
The amount of bound peroxidase is proportional to the concentration of LH in the sample.
Having added the substrate solution, the intensity of colour developed is proportional to the concentration of LH in the patient sample.
WARNINGS AND PRECAUTIONS
This kit is for in vitro diagnostic use only. For professional use only.
All reagents of this test kit which contain human serum or plasma have been tested and confirmed negative for HIV I/II, HBsAg and
HCV by FDA approved procedures. All reagents, however, should be treated as potential biohazards in use and for disposal.
Before starting the assay, read the instructions completely and carefully. Use the valid version of the package insert provided with the
kit. Be sure that everything is understood.
The microplate contains snap-off strips. Unused wells must be stored at 2 °C to 8 °C in the sealed foil pouch and used in the frame
Pipetting of samples and reagents must be done as quickly as possible and in the same sequence for each step.
Use reservoirs only for single reagents. This especially applies to the substrate reservoirs. Using a reservoir for dispensing a
substrate solution that had previously been used for the conjugate solution may turn solution colored. Do not pour reagents back into
vials as reagent contamination may occur.
Mix the contents of the microplate wells thoroughly to ensure good test results. Do not reuse microwells.
Do not let wells dry during assay; add reagents immediately after completing the rinsing steps.
Allow the reagents to reach room temperature (21-26°C) before starting the test. Temperature will affect the absorbance readings of
the assay. However, values for the patient samples will not be affected.
10. Never pipet by mouth and avoid contact of reagents and specimens with skin and mucous membranes.
11. Do not smoke, eat, drink or apply cosmetics in areas where specimens or kit reagents are handled.
12. Wear disposable latex gloves when handling specimens and reagents. Microbial contamination of reagents or specimens may give
13. Handling should be done in accordance with the procedures defined by an appropriate national biohazard safety guideline or
14. Do not use reagents beyond expiry date as shown on the kit labels.
15. All indicated volumes have to be performed according to the protocol. Optimal test results are only obtained when using calibrated
16. Do not mix or use components from kits with different lot numbers. It is advised not to exchange wells of different plates even of the
same lot. The kits may have been shipped or stored under different conditions and the binding characteristics of the plates may result
17. Avoid contact with Stop Solution
containing 0.5 M H2SO4. It may cause skin irritation and burns.
18. Some reagents contain Proclin 300, BND and/or MIT as preservatives. In case of contact with eyes or skin, flush immediately with
19. TMB substrate has an irritant effect on skin and mucosa. In case of possible contact, wash eyes with an abundant volume of water
and skin with soap and abundant water. Wash contaminated objects before reusing them. If inhaled, take the person to open air.
20. Chemicals and prepared or used reagents have to be treated as hazardous waste according to the national biohazard safety guideline
21. For information on hazardous substances included in the kit please refer to Material Safety Data Sheets.
Material Safety Data Sheets for this product are available upon request directly from DIAsource.
12 x 8 (break apart) strips, 96 wells.
Wells coated with anti-LH monoclonal antibody.
. N= 0 to 5, 6 vials (lyophilized), 1 mL
Concentration : 0; 10; 20; 40; 100 ; 200 mlU/mL
The calibrators are calibrated against WHO 2nd International Calibrator for LH IRP (80/552)
Contain 0.03% Proclin 300, 0.015% BND and 0.010% MIT as preservative.
, 1 vial, 11 mL. Ready for use.
Anti-LH antibody conjugated to horseradish peroxidase.
Contains 0.03 % Proclin 300, 0.015 % BND and 0.010 % Mit as preservative.
4. CHROM TMB
, 1 vial, 14 mL. Ready for use.
Avoid contact with the stop solution. It may cause skin irritations and burns.
Additional Calibrator 0
for sample dilution is available on request.
Material required but not provided
− A microtiter plate calibrated reader (450 ± 10 nm)
− Calibrated variable precision micropipettes.
− Semi logarithmic graph paper or software for data reduction
When stored at 2 °C to 8 °C unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.
Opened reagents must be stored at 2 °C to 8 °C. Microtiter wells must be stored at 2 °C to 8 °C. Once the foil bag has been opened, care
should be taken to close it tightly again.
Opened kits retain activity for six weeks if stored as described above.
Bring all reagents and required number of strips to room temperature prior to use.
Reconstitute the lyophilized contents of the calibrator vial with 1 mL Aqua dest. Note: The reconstituted calibrators are stable for 2 months at 2 °C to 8 °C. For longer storage freeze at –20 °C.
Disposal of the Kit
The disposal of the kit must be made according to the national regulations. Special information for this product is given in the Material Safety
Damaged Test Kits
In case of any severe damage to the test kit or components, DIAsource has to be informed in writing, at the latest, one week after receiving
the kit. Severely damaged single components should not be used for a test run. They have to be stored until a final solution has been found.
After this, they should be disposed according to the official regulations.
SPECIMEN COLLECTION AND PREPARATION
Only serum should be used in this assay.
Do not use haemolytic, icteric or lipaemic specimens. Please note:
Samples containing sodium azide should not be used in the assay.
Collect blood by venipuncture (e.g. Sarstedt Monovette # 02.1388.001), allow to clot, and separate serum by centrifugation at room
temperature. Do not centrifuge before complete clotting has occurred. Patients receiving anticoagulant therapy may require increased
Specimen Storage and Preparation
Specimens should be capped and may be stored for up to 48 hours at 2 °C to 8 °C prior to assaying.
Specimens held for a longer time should be frozen only once at -20°C prior to assay. Thawed samples should be inverted several times prior
If in an initial assay, a specimen is found to contain more than the highest calibrator, the specimens can be diluted with Calibrator 0
reassayed as described in Assay Procedure.
For the calculation of the concentrations this dilution factor has to be taken into account.
10 µL Serum + 90 µL Calibrator 0
10 µL dilution a) 1:10 + 90 µL Calibrator 0
All reagents and specimens must be allowed to come to room temperature before use. All reagents must be mixed without
Once the test has been started, all steps should be completed without interruption.
Use new disposal plastic pipette tips for each calibrator, control or sample in order to avoid cross contamination
Absorbance is a function of the incubation time and temperature. Before starting the assay, it is recommended that all reagents are
ready, caps removed, all needed wells secured in holder, etc. This will ensure equal elapsed time for each pipetting step without
As a general rule the enzymatic reaction is linearly proportional to time and temperature.
Pipetting of all calibrators, samples, and controls should be completed within 6 minutes. (note this especially for manual
Each run must include a calibration curve.
Secure the desired number of Microtiterwells in the holder.
Dispense 25 µL
of each Calibrator, controls
and samples with new disposable tips into appropriate wells.
Dispense 100 µL Enzyme Conjugate
into each well.
Thoroughly mix for 10 seconds. It is important to have a complete mixing in this step.
Incubate for 30 minutes
at room temperature.
Briskly shake out the contents of the wells. Rinse the wells 5 times
with aqua dest (400 µL per well). Strike the wells sharply on
absorbent paper to remove residual droplets. Important note:
The sensitivity and precision of this assay is markedly influenced by the correct performance of the washing procedure!
Add 100 µL
of Substrate Solution
to each well.
Incubate for 10 minutes
at room temperature.
Stop the enzymatic reaction by adding 50 µL
of Stop Solution
to each well.
Determine the absorbance (OD) of each well at 450 ± 10 nm
with a microtiter plate reader.
It is recommended that the wells be read within 10 minutes
after adding the Stop Solution
Calculation of Results
Calculate the average absorbance values for each set of calibrators, controls and patient samples.
Using semi-logarithmic graph paper, construct a calibration curve by plotting the mean absorbance obtained from each
calibrator against its concentration with absorbance value on the vertical(y) axis and concentration on the horizontal (x) axis.
Using the mean absorbance value for each sample determine the corresponding concentration from the calibration curve.
Automated method: the results in the ifu have been calculated automatically using a 4 pl (4 parameter logistics) curve fit.
4 parameter logistics is the preferred method. Other data reduction functions may give slightly different results.
The concentration of the samples can be read directly from this calibration curve. Samples with concentrations higher than that of
the highest calibrator have to be further diluted or reported as > 200 miu/ml. For the calculation of the concentrations this
dilution factor has to be taken into account.
Example of Typical Calibration Curve
The following data is for demonstration only and cannot
be used in place of data generations at the time of assay.
Optical Units (450 nm)
EXPECTED NORMAL VALUES
It is strongly recommended that each laboratory should determine its own normal and abnormal values.
In a study conducted with apparently normal healthy adults, using the DIAsource LH ELISA the following values are observed:
The results alone should not be the only reason for any therapeutic consequences. The results should be correlated to other clinical
Good laboratory practice requires that controls be run with each calibration curve. A statistically significant number of controls should be
assayed to establish mean values and acceptable ranges to assure proper performance.
It is recommended to use control samples according to state and federal regulations. The use of control samples is advised to assure the
day to day validity of results. Use controls at both normal and pathological levels.
The controls and the corresponding results of the QC-Laboratory are stated in the QC certificate added to the kit. The values and ranges
stated on the QC sheet always refer to the current kit lot and should be used for direct comparison of the results.
It is also recommended to make use of national or international Quality Assessment programs in order to ensure the accuracy of the results.
Employ appropriate statistical methods for analysing control values and trends. If the results of the assay do not fit to the established
acceptable ranges of control materials patient results should be considered invalid.
In this case, please check the following technical areas: Pipetting and timing devices; photometer, expiration dates of reagents, storage and
incubation conditions, aspiration and washing methods.
After checking the above mentioned items without finding any error contact your distributor or DIAsource directly.
Assay Dynamic Range
The range of the assay is between 1.27 – 200 mIU/mL.
Specificity of Antibodies (Cross Reactivity)
The following substances were tested for cross reactivity of the assay:
Produced Color Intensity
Equivalent to LH in Serum (mIU/mL)
Pregnancy results in elevated levels of hCG, the use of the LH enzyme immunoassay test is not recommended during pregnancy or
The analytical sensitivity of the DIAsource ELISA was calculated by adding 2 standard deviations to the mean of 20 replicate analyses of the
Zero Calibrator (S0) and was found to be 1.27 mIU/mL.
The within assay variability is shown below:
The between assay variability is shown below:
Samples have been spiked by adding LH solutions with known concentrations in a 1:1 ratio.
The % Recovery has been calculated by multiplication of the ratio of the measurements and the expected values with 100.
(* Endogenous LH / 2 + added LH because of a 1:1 dilution of serum with spike material.)
10 LIMITATIONS OF USE
Reliable and reproducible results will be obtained when the assay procedure is performed with a complete understanding of the package
insert instruction and with adherence to good laboratory practice. Any improper handling of samples or modification of this test might influence the results.
Haemoglobin (up to 4 mg/mL), Bilirubin (up to 0.5 mg/mL) and Triglyceride (up to 30 mg/mL) have no influence on the assay results.
Until today no substances (drugs) are known to us, which have an influence to the measurement of LH in a sample.
No hook effect was observed in this test up to 10,000 mIU/mL of LH.
11 LEGAL ASPECTS
Reliability of Results
The test must be performed exactly as per the manufacturer’s instructions for use. Moreover the user must strictly adhere to the rules of
GLP (Good Laboratory Practice) or other applicable national calibrators and/or laws. This is especially relevant for the use of control
reagents. It is important to always include, within the test procedure, a sufficient number of controls for validating the accuracy and precision
The test results are valid only if all controls are within the specified ranges and if all other test parameters are also within the given assay
specifications. In case of any doubt or concern please contact DIAsource.
Therapeutic consequences should never be based on laboratory results alone even if all test results are in agreement with the items as
stated under point 11.1. Any laboratory result is only a part of the total clinical picture of a patient.
Only in cases where the laboratory results are in acceptable agreement with the overall clinical picture of the patient should therapeutic
The test result itself should never be the sole determinant for deriving any therapeutic consequences.
Any modification of the test kit and/or exchange or mixture of any components of different lots from one test kit to another could negatively
affect the intended results and validity of the overall test. Such modification and/or exchanges invalidate any claim for replacement.
Claims submitted due to customer misinterpretation of laboratory results subject to point 11.2. are also invalid. Regardless, in the event of
any claim, the manufacturer’s liability is not to exceed the value of the test kit. Any damage caused to the test kit during transportation is not
subject to the liability of the manufacturer.
Harris, G.W. and Naftolinf., The Hypothalamus and Control of Ovulation,
Knobil, E., The Neuroendocrine Control of the Menstrual Cycle,
Jeffcoate, S.L., Clinics in Endocrinol. Metab., 4, 521-543 (1975).
Whitely, R.J., Keutmann, H.T. and Ryan, R.J., Endocrinology, 102, 1874 (1978).
Pierce, J.G. and Parsons, T.F., Glycoprotein hormones: Structure and Function,
Annual Rev. Biochem., 50, 465-495 (1981).
Bardin , C.W. and Paulsen, C.A., "The Testes" in Textbook of Endocrinology, (ed.) R.H. Williams M.D., W.B. Saunders Co., (1981).
Shome, B. and Parlow, A.F., J. Clin. Endocrinol. Metabl., 39, 199-202 (1974).
Shome, B. and Parlow, A.F., J. Clin. Endocrinol. Metabl., 39, 203-205 (1974).
Ross, G.T., VandeWeile, R.L., and Frantz, A.G. Chapter 7 in "The Ovaries and the Breasts" in "Textbook of Endocrinology" (R. H.
Williams, Ed.), W.B. Saunders Co. (1981).
10. Marshall, J.C., Clinics in Endocrinal Metab., 4, 545-567 (1975). 11. Acosta, A.A.M.D. and Wright, G.L., Journal of Clinical Immunoassays, 6, 41 (1983). 12. Brown, J. Wood (eds.), Churchill Livingston Co., New York, 7-42 (1980). 13. Yen, S.S.C., Vela, P. and Rankin, J., J. Clin. Endocrinol. Metab., 30, 434-442 (1970). 14. Cohen, K. L., Metabolism, 26, 1165-1177 (1977). 15. Engvall, E., Methods in Endocrinology, Volume 70, Van Vunakis, H. and Langone, J.J. (eds.),
Academic Press, New York, 419-492 (1980).
16. Uotila, M. Ruoslahti,E. and Engvall, E., J. Immunol. Methods, 42, 11-15 (1981).
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