Product Features
Product Name Human TIMP-2 EasyTest™ ELISA Kit Assay Type Solid Phase Sandwich ELISA Format 96-well strip plate Assay Process One wash step, two incubations Assay Length 1.5 hours Sample Volume Serum , Plasma, 50µL Detection Method Colorimetric Sensitivity 3pg/mL Assay Range 65.5-16000pg/mL Reactivity Human Cross-Reactivity No cross-reactivity observed with available related molecules Gene Names TIMP2; CSC-21K; DDC8 Gene ID 7077 Swissprot ID P16035
Recovery
| Sample Type | Average % Recovery | Range % |
| Serum | 97 | 81-119 |
| Plasma | 131 | 127-137 |
Linearity
| Sample Type | Dilution | % of Expected |
| Serum | 1:2 | 88 |
| 1:4 | 77 | |
| 1:8 | 85 | |
| Plasma | 1:2 | 104 |
| 1:4 | 98 | |
| 1:8 | 93 |
Standard Curve: Human TIMP-2 EasyTest™ ELISA Kit
Kit Components
• Pre-Coated 96-well Strip Microplate • Wash Buffer • Stop Solution • Assay Diluent • Standards • Bioaim human TIMP-2 mix • TMB One-Step Substrate
Protocol Outline
1. Prepare all reagents, samples and standards as instructed in the manual. 2. Add 50 µl of standard or sample to each well. 3. Add 50 µl of Bioaim mix. 4. Incubate 1 h at RT. 5. Wash and add 100 µl of TMB One-Step Substrate Reagent to each well. 6. Incubate 15 min at RT. 7. Add 50 µl of Stop Solution to each well. 8. Read at 450 nm/570 nm.
Background
TIMPs-1 through -4 regulate the activity of zinc metalloproteases known as MMPs, ADAMs and ADAMTSs. Structurally, TIMPs contain two domains. The N-terminal domain binds to the active site of mature metalloproteases via a 1:1 non-covalent interaction, blocking access of substrates to the catalytic site. In addition, The C-terminal domain of TIMP-1 and TIMP-2 binds to the hemopexin- like domain of pro-MMP-9 and pro-MMP-2, respectively. The latter binding is essential for the cell surface activation of MMP-2 by MMP-14. TIMP-2 functions as both an MMP inhibitor and an activator. TIMPs inhibit all active MMPs, but different TIMPs inhibit different MMPs better than other TIMPs. For example, TIMP-1 inhibits MMP-7, MMP-9, MMP-1 and MMP-3 better than TIMP-2, and TIMP-2 inhibits MMP-2 more effectively than other TIMPs.
Storage
The entire kit may be stored at -20°C for up to 1 year from the date of shipment. Avoid repeated freeze-thaw cycles. The kit may be stored at 4°C for up to 6 months. For extended storage, it is recommended to store at -80°C.
Regulatory Status
Human TIMP-2 EasyTest™ ELISA Kit is for Research Use Only.
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采用抗-HBe抗体包被反应板，加入校准品及被测样本，同时加入定量HBeAg中和抗原，经过振荡孵育,洗板后再加入铕标记的抗-HBe，若标本中抗-HBe浓度高，HBeAg将被大量中和，使最后形成的抗-HBe-HBeAg-铕标记抗-HBe复合物减少。增强液（β－NTA）将标记在抗体上的Eu3+解离到溶液中，Eu3+和增强液中的有效成分形成高荧光强度的螯合物，荧光强度和样本中的抗-HBe浓度成反比。
1、直接竞争，标记抗原，与检测样品中的抗原竞争抗体。
2、间接竞争，标记抗体，固相抗原与液相抗原（样品）竞争标记抗体。
3、定义
间接竞争法的模型：包被抗原，用HRP-抗体与样本一起加入。样本中的Ag与Solid-Ag竞争HRP-Ab，固相吸附的HRP-Ab与样本中的Ag浓度成反比。
直接竞争法的模型：包被抗体，用HRP-抗原与样本一起加入。样本中的Ag与HRP-Ag竞争Solid-Ab，固相吸附的HRP-Ag与样本中的Ag浓度成反比。
4、竞争法的理论基础：是限量抗体。只有在限量抗体基础上，两种抗原才会形成竞争关系。
5、、间接竞争法具备较高灵敏度原因。
直接竞争法里，标记抗原与待测抗原均是液相，与抗体的结合机会是一样的，例如有1份标记抗原与1份待测抗原竞争1份抗体，那么有50%的标记抗原能与抗体结合，所以标记抗原的相对结合率为50%。间接法里，固相抗原与抗体的接触面积较小，固相抗原与待测抗原的结合抗体机会是不平等的，接近顺序饱和法，即只有与待测抗原结合剩余的抗体才会与固相抗原结合，同样有1份固相抗原与1份待测抗原竞争1份抗体时，基本上抗体会被待测抗原中和掉，与固相抗原结合的抗体非常少。固相抗原的相对结合率为0%。因此，间接法的抑制曲线斜率会大于竞争法。
因为抑制率越大则斜率越大，从而灵敏度越大。（假设零管变异5%，以两倍SD为灵敏度限，则为90%相对结合率，则间接法可以在较低的待测抗原浓度达到这一相对结合率，因此灵敏度要高。）
在进行系统放大时，间接法一般可以使用酶标二抗。因为二抗可以针对抗体的多个部位，所以存在放大效应，从而能提高间接法的灵敏度。直接法一般难以进行放大，常用的有生物 素化抗原与酶标亲和素，但模式上似乎不存在放大效应。
6、间接法的高灵敏度难以实现的原因：
双抗体 夹心的免放（IRMA）模式刚出现时，也被模型证明灵敏度优于竞争法的放免（RIA），原因也是较大的斜率，但是IRMA的高灵敏度一直到单抗发展后才得以实现。
