Description:

ProductName:LH

#ofSamples:1x96Assays

IntendedUse:Immunoenzymaticcolorimetricmethod(ELISA)forquantitativedeterminationofLHinserum.

Introduction:Luteinizinghormone(LH)isaglycoproteinconsistingoftwosubunitswithamolecularmassof30,000daltons.Theα-subunitissimilartootherpituitaryhormones[folliclestimulatinghormone(FSH),thyroidstimulatinghormone(TSH)andchorionicgonadotropin(HCG)]whiletheβ-subunitisunique.Theβ-subunitconferstheBIOLOGicalactivitytothemolecule.
Theα-subunitconsistsof89aminoacidresidueswhiletheβ-subunitcontains129aminoacids.Thecarbohydratecontentisbetween15%and30%.Theclinicalusefulnessofthemeasurementofluteinizinghormone(LH)inascertainingthehomeostasisoffertilityregulationviathehypothalamic-pituitary-gonadalaxishasbeenwellestablished(1,2).Inaddition,theadventofinvitrofertilization(IVF)technologytoovercomeinfertilityassociatedproblemshasprovidedtheimpetusforrapidimprovementinLHassaymethodologyfromthetechnicallydemandingbioassaytotheprocedurallysimpleandrapidimmunoenzymometricassays.

Principlesoftheassay:Inthismethod,LHstandards,patientspecimensand/orcontrols(containingthenativeantigen)arefirstaddedtostreptavidincoatedwells.Biotinylatedmonoclonalandenzymelabeledantibodiesareaddedandthereactantsmixed:theseantibodieshavehighaffinityandspecificityandaredirectedagainstdistinctanddifferentepitopesofLH.ReactionbetweenthevariousLHantibodiesandnativeLHoccursinthemicrowellswithoutcompetitionorsterichindranceformingasolublesandwichcomplex.
Theinteractionisillustratedbythefollowingequation:

ka
EnzAb+AgLH+BtnAb(m)?EnzAb-AgLH-BtnAb(m)
k-a

BtnAb(m)=BiotinylatedMonoclonalAntibody(ExcessQuantity)
AgLH=NativeAntigen(VariableQuantity)
EnzAb(p)=EnzymelabeledAntibody(ExcessQuantity)
EnzAb(p)-AgLH-BtnAb(m)=Antigen-AntibodiesSandwichComplex
ka=RateConstantofAssociation
k-a=RateConstantofDissociation

Simultaneously,thecomplexisdepositedtothewellthroughthehighaffinityreactionofstreptavidinandbiotinylatedantibody.Thisinteractionillustratedbelow:

EnzAb-AgLH-BtnAb(m)+StreptavidinC.W.?????Immobilizedcomplex

StreptavidinC.W.=Streptavidinimmobolizedonwell.
Immobilizedcomplex=Antibodies-Antigensandwichbound.

Afterequilibriumisattained,theantibody-boundfractionisseparatedfromunboundantigenbydecantationoraspiration.Theenzymeactivityintheantibody-boundfractionisdirectlyproportionaltothenativeantigenconcentration.Theactivityoftheenzymepresentonthesurfaceofthewellquantitatedbyreactionwithasuitablesubstratetoproducecolour.Byutilizingseveraldifferentcalibratorsofknownantigenvalues,adoseresponsecurvecanbegeneratedfromwhichtheantigenconcentrationofanunknowncanbeascertained

StorageandStABIlity:Thereagentsarestableuptotheexpirydatestatedonthelabelwhenstoredat+2...+8°Cinthedark.
Openedreagentsarestablefor60dayswhenstoredat+2...+8°C.


LimitationsoftheTest:Bacterialcontaminationorrepeatedfreeze-thawcyclesofthespecimenmayaffecttheabsorbancevalues.
LHissuppressedbyestrogenbutinwomantakingoralcontraceptivesthelevelmaybelowornormal.Excessivedietingandweightlossmayleadtolowgonadotropinconcentrations.Luteinizinghormoneisdependentupondiversefactorsotherthanpituitaryhomeostasis.Thus,thedeterminationaloneisnotsufficienttoassessclinicalstatus

ReferencesKosasaT.S.,"MeasurementofHumanLuteinizingHormone."JournalofReproductiveMedicine,26(1981)pg.201-6.2.DanzerH.,BraunsteinG.D.,etal.,"MaternalSerumHumanChorionicGonadotropicConcentrationsandFetalSexPredictions."FertilityandSterility,34(1980)pg.336-40.3.BraunsteinG.D.,etat.,"SerumHumanLuteinizingHormoneLevelsthroughNormalPregnancy",AmericanJournalofObstetricsandGynecology,126(1976)pg.678-81.4.GoldsteinD.P.,andKosasaT.S.,"TheSubunitRADIoimmunoassayforLHClinicalApplication."Gynecology,6(1975)pg.145-84.5.BatzerF.,"HormonalEvaluationofEarlyPregnancy",FertilityandSterility,34(1980)pg.1-12.6.Braunstein,G.D.,etal.,"First-TrimesterLuteinizingHormoneMeasurementsasanAidtotheDiagnosisofEarlyPregnancyDisorders”,AmericanJournalofObstetricsandGynecology,131(1978)pg.25-32.7.LentonE.,NealL.andSulaimanR.,"PlasmaConcentrationsofHumanGonadotropinfromthetimeofImplantationuntiltheSecondWeekofPregnancy",FertilityandSterility,37(1982)pg.773-78.

AdditionalInformation:

Name	LH
RelatedProductNames	LH
MolecularWeight	0.5
Storage	Thereagentsarestableuptotheexpirydatestatedonthelabelwhenstoredat+2...+8°Cinthedark. Openedreagentsarestablefor60dayswhenstoredat+2...+8°C.
IntendedUse	ResearchUseOnly