Description:

Product Name: LH# of Samples: 1 x 96 AssaysIntended Use: Immunoenzymatic colorimetric method (ELISA) for quantitative determination of LH in serum. Introduction: Luteinizing hormone (LH) is a glycoprotein consisting of two subunits with a molecular mass of 30,000 daltons. The α-subunit is similar to other pituitary hormones [follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH) and chorionic gonadotropin (HCG)] while the β-subunit is unique. The β-subunit confers the biological activity to the molecule.The α -subunit consists of 89 amino acid residues while the β-subunit contains 129 amino acids. The carbohydrate content is between 15% and 30%. The clinical usefulness of the measurement of luteinizing hormone (LH) in ascertaining the homeostasis of fertility regulation via the hypothalamic -pituitary - gonadal axis has been well established (1,2). In addition, the advent of in vitro fertilization (IVF) technology to overcome infertilityassociated problems has provided the impetus for rapid improvement in LH assay methodology from the technically demanding bioassay to the procedurally simple and rapid immunoenzymometric assays.Principles of the assay: In this method, LH standards, patient specimens and/or controls (containing the native antigen) are first added to streptavidin coated wells. Biotinylated monoclonal and enzyme labeled antibodies are added and the reactants mixed: these antibodies have high affinity and specificity and are directed against distinct and different epitopes of LH. Reaction between the various LH antibodies and native LH occurs in the microwells without competition or steric hindrance forming a soluble sandwich complex.The interaction is illustrated by the following equation:kaEnzAb + Ag LH + BtnAb(m) ? EnzAb - AgLH-BtnAb(m)k-aBtnAb(m) = Biotinylated Monoclonal Antibody (Excess Quantity)AgLH = Native Antigen (Variable Quantity)EnzAb(p) = Enzyme labeled Antibody (Excess Quantity)EnzAb(p)-AgLH-BtnAb(m) = Antigen-Antibodies Sandwich Complexka = Rate Constant of Associationk-a = Rate Constant of DissociationSimultaneously, the complex is deposited to the well through the high affinity reaction of streptavidin and biotinylated antibody. This interaction illustrated below:EnzAb -AgLH-BtnAb(m) + StreptavidinC.W. ? ????Immobilized complexStreptavidin C.W. = Streptavidin immobolized on well.Immobilized complex = Antibodies-Antigen sandwich bound.After equilibrium is attained, the antibody-bound fraction is separated from unbound antigen by decantation or aspiration. The enzyme activity in the antibody-bound fraction is directly proportional to the native antigen concentration. The activity of the enzyme present on the surface of the well quantitated by reaction with a suitable substrate to produce colour. By utilizing several different calibrators of known antigen values, a dose response curve can be generated from which the antigen concentration of an unknown can be ascertainedStorage and Stability: The reagents are stable up to the expiry date stated on the label when stored at +2...+8 °C in the dark.Opened reagents are stable for 60 days when stored at +2...+8 °C.Limitations of the Test: Bacterial contamination or repeated freeze-thaw cycles of the specimen may affect the absorbance values.LH is suppressed by estrogen but in woman taking oral contraceptives the level may be low or normal. Excessive dieting and weight loss may lead to low gonadotropin concentrations. Luteinizing hormone is dependent upon diverse factors other than pituitary homeostasis. Thus, the determination alone is not sufficient to assess clinical statusReferences Kosasa T.S., \"Measurement of Human Luteinizing Hormone.\" Journal of Reproductive Medicine, 26 (1981) pg. 201-6.2. Danzer H., Braunstein G.D., et al., \"Maternal Serum Human Chorionic Gonadotropic Concentrations and Fetal Sex Predictions.\" Fertility and Sterility, 34 (1980) pg. 336-40.3. Braunstein G.D., et at., \"Serum Human Luteinizing Hormone Levels through Normal Pregnancy \", American Journal of Obstetrics and Gynecology, 126 (1976) pg. 678-81.4. Goldstein D.P., and Kosasa T.S., \"The Subunit Radioimmunoassay for LH Clinical Application.\" Gynecology, 6 (1975) pg. 145-84.5. Batzer F., \"Hormonal Evaluation of Early Pregnancy\", Fertility and Sterility, 34 (1980) pg. 1-12.6. Braunstein, G.D., et al., \"First-Trimester Luteinizing Hormone Measurements as an Aid to the Diagnosis of Early Pregnancy Disorders”, American Journal of Obstetrics and Gynecology, 131 (1978) pg. 25-32.7. Lenton E., Neal L. and Sulaiman R., \"Plasma Concentrations of Human Gonadotropin from the time of Implantation until the Second Week of Pregnancy \", Fertility and Sterility, 37 (1982) pg. 773-78.

Additional Information:

Name Related Product Names Molecular Weight Storage Intended Use

LH

LH

0.5

The reagents are stable up to the expiry date stated on the label when stored at +2...+8 °C in the dark.Opened reagents are stable for 60 days when stored at +2...+8 °C.

Research Use Only