| Kitsize | 12x8 |
| Method | ELISA |
| Incubationtime | 1x1h(RTS),1x30min(RTS),1x15min |
| Standardrange | 42-1050ng/mL(1:21dil.)or20-500ng/mL(1:10dil.) |
| Specimen/Volumes | 10µLSerumorPlasma |
| Substrate/isotope | TMB,450nm |
| RegulatoryStatus: | EU:CE |
Anon-extractionassaywith
highspecificity
Themeasurementofinsulin-likegrowthfactor-I(IGF-I)inserumisofespeciallyhighutilityinthediagnosticwork-upofgrowthdisturbances,particularlywithregardtohumangrowthhormone(hGH)deficiencyoracromegaly.ThemostimportantadvantageofmeasuringIGF-IoverhGHareitsstablecircADIanlevels,i.e.evenasinglemeasurementisofconclusivesignificance.
Inviewoftheabove,measurementofIGF-Ishouldbeputonthefrontburnerinlaboratorydiagnosticwork-up.
TheadvantagesofourELISAsare:
- non-extractionassay;
- highspecificityforIGF-I;
- nointerferencefromIGF-bindingproteins(IGFBP);
- onlyasamplevolumeof10µLrequired;
- onesampledilutionsuffices(usually1:21);
- calibratedagainsttheinternationalstandardofWHONIBSC02/254;
- veryhighsensitivity(0.09ng/mL);
- outstandingaccuracy--98.7%recovery;
- remarkableprecision:inter-assayvarianceof6.8%andintra-assayvarianceof6.7%.
IBLInternational´sIGF-Ienzymelinkedimmunosorbentassay(ELISA)byIBLInternationalisusedformeasuringIGF-Iinhumanserum/plasma,cerebrospinalfluidandotherbodyfluidsaswellasinconditionedcellculturemediaofmanyhumancelllines.
Whatismore,theassaycanalsobeusedforthemeasurementofIGF-Iinothermammalssuchasprimates,cattle,pig,sheep,horse,donkey,goat,dog,cat,rabbitandguineapig.However,thekitisnotsuitedforrat,mouseandchickensamples
Insulin-likegrowthfactorsIandII(IGF-I,IGF-II)playakeyroleinproliferation,differentiationandspecificfunctionsofmanycelltypes.IGF-IisidenticaltosomatomedinC(Sm-C)andisregulatedbythegrowthhormone(hGH/GH)andnutrition.Unlikemanyotherpeptidehormones,IGFsareboundtospecificbindingproteins(IGFBP)withahighaffinity.AsubstantialprobleminthemeasurementofIGF-IlevelsistheinterferencebyIGFBPs.Whenmeasuredinuntreatedserumsamples,inaccurateresultsareobtainedduetotheextremelyslowdissociationoftheIGF-I/IGFBP-3complexduringassayincubation.Forthisreason,onlyafractionofIGF-Iisavailableformeasurement.InterferencesaredeterminedbytheIGF-ItoIGFBPratiointhesample.

Inordertocircumventthisproblem,asimpleassaywasdevelopedinwhichsamplesareacidifiedanddilutedusingabufferofaspecialcompositionpriortoperformingELISA.
ClinicalSignificance
ApartfromhGH,anumberofotherfactorsaffectserumIGF-Ilevels.Lowvaluesarefoundinmalnutrition/malabsorption,hypothyroidism,liverdisease,untreateddiabetesmellitus,chronicinflammatorydiseases,malignanciesandmultipletrauma.Elevatedlevels,ontheotherhand,arefoundinprecociouspubertyandobesity.
InordertobeabletocorrectlyinterpretIGFmeasurements,itisofutmostimportancetoconsidertheage-dependentpatternofIGF-1levels,whichyoucanfindintheInstructionforUse.
| Percentiles | |||||
| Pubertätsstadium | 0.1th | 5th | 50th | 95th | PubertalStage |
| 1 | 61 | 105 | 186 | 330 | 1 |
| 2 | 85 | 156 | 298 | 568 | 2 |
| 3 | 113 | 196 | 352 | 631 | 3 |
| 4 | 171 | 268 | 431 | 693 | 4 |
| 5 | 165 | 263 | 431 | 706 | 5 |

Figure3:Age-dependentreferencerangeforIGF-Ilevelsinboys(ageinyears)


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1. 直接法测定抗原 2.间接法测定抗体 3.双抗体夹心法测定抗原4. 竞争法测定抗原 厚百生物专业提供各类生化实验试剂、仪器、耗材,提供技术服务,满足您的实验室常规采购需求。厚百,让您更省心!
(1) 包被:用0.05M PH9.牰碳酸盐包被缓冲液将抗体稀释至蛋白质含量为1~10μg/ml。在每个聚苯乙烯板的反应孔中加0.1ml,4℃过夜。次日,弃去孔内溶液,用洗涤缓冲液洗3次,每次3分钟。(简称洗涤,下同)。
(2) 加样:加一定稀释的待检样品0.1ml于上述已包被之反应孔中,置37℃孵育1小时。然后洗涤。(同时做空白孔,阴性对照孔及阳性对照孔)。
(3) 加酶标抗体:于各反应孔中,加入新鲜稀释的酶标抗体(经滴定后的稀释度)0.1ml。37℃孵育0.5~1小时,洗涤。
(4) 加底物液显色:于各反应孔中加入临时配制的TMB底物溶液0.1ml,37℃10~30分钟。
(5) 终止反应:于各反应孔中加入2M硫酸0.05ml。
(6) 结果判定:可于白色背景上,直接用肉眼观察结果:反应孔内颜色越深,阳性程度越强,阴性反应为无色或极浅,依据所呈颜色的深浅,以“+”、“-”号表示。也可测O·D值:在ELISA检测仪上,于450nm(若以ABTS显色,则410nm)处,以空白对照孔调零后测各孔O·D值,若大于规定的阴性对照OD值的2.1倍,即为阳性。
间接法:
用包被缓冲液将已知抗原稀释至1~10μg/ml,每孔加0.1ml,4℃过夜。次日洗涤3次。加一定稀释的待检样品(未知抗体)0.1ml于上述已包被之反应孔中,置37℃孵育1小时,洗涤。(同时做空白、阴性及阳性孔对照)于反应孔中,加入新鲜稀释的酶标第二抗体(抗抗体)0.1ml,37℃孵育30-60分钟,洗涤,最后一遍用DDW洗涤。其余步骤同“双抗体夹心法”的4、5、6。
表面抗体是双抗原夹心法
E抗体和核心抗体是竞争抑制法或间接法
1. 包被:用0.05M PH9,碳酸盐包被缓冲液将抗体稀释至蛋白质含量为1~10μg/ml,在每个聚苯乙烯板的反应孔中加0.1ml,4℃过夜。次日,弃去孔内溶液,用洗涤缓冲液洗3次,每次3分钟。
2. 加样:加一定稀释的待检样品0.1ml于上述已包被之反应孔中,置37℃孵育1小时。然后洗涤。(同时做空白孔,阴性对照孔及阳性对照孔)。
3. 加酶标抗体:于各反应孔中,加入新鲜稀释的酶标抗体(经滴定后的稀释度)0.1ml,37℃孵育0.5~1小时,洗涤。
4. 加底物液显色:于各反应孔中加入临时配制的TMB底物溶液0.1ml,37℃10~30分钟。
5. 终止反应:于各反应孔中加入2M硫酸0.05ml。
6. 结果判定:可于白色背景上,直接用肉眼观察结果:反应孔内颜色越深,阳性程度越强,阴性反应为无色或极浅,依据所呈颜色的深浅,以“+”、“-”号表示。也可测OD值:在ELISA检测仪上,于450nm(若以ABTS显色,则410nm)处,以空白对照孔调零后测各孔OD值,若大于规定的阴性对照OD值的2.1倍,即为阳性。
方法二:用于检测未知抗体的间接法:
用包被缓冲液将已知抗原稀释至1~10μg/ml,每孔加0.1ml,4℃过夜。次日洗涤3次。加一定稀释的待检样品(未知抗体)0.1ml于上述已包被之反应孔中,置37℃孵育1小时,洗涤。(同时做空白、阴性及阳性孔对照)于反应孔中,加入新鲜稀释的酶标第二抗体(抗抗体)0.1ml,37℃孵育30~60分钟,洗涤,最后一遍用DDW洗涤。其余步骤同“双抗体夹心法”的4、5、6。

