Immuno-Oncology Studies

An Introduction to Immunohistochemistry

Immunohistochemistry (IHC) is an assay that utilizes the biological collaboration of Histology and Immunology. The biochemical interactions between an antibody and antigen permit visual distribution and localization of antibody–antigen interactions. This allows morphology, antigen intensity, and spatial relationships to be determined.

景offers high-quality IHC assays onsite to give you a time-efficient read-out on quantitative and qualitative data. With our in-house IHC services, data can be produced expeditiously that reveals the following:

  • Efficacy of your compound in target tissues
  • Location of biomarkers in tissues
  • 肿瘤转移的发病率
  • 将组织转化成肿瘤的发生
  • Origin of tumor tissue
  • 研究中的动物预后

Steps to Performing Immunohistochemistry

图1:IHC固定和表位检索*

通过一系列样品制剂获得IHC结果,允许操纵组织以用于抗原发现。手术移除组织并置于固定剂(如NBF或PFA)中。在固定期间,组织经历一种化学反应,其中核酸和胺形成由亚甲基桥组成的半可逆交叉链路(图1)。交叉链接产生细胞和组织稳定性,并保护组织免受分解和蛋白水解酶的损伤。然后可以将固定组织储存在石蜡中,使其在IHC的任何未来时间使用它们。

已经固定的样品必须经历抗原检索方法以检测抗原。在载玻片上切割和安装后,必须再水化组织以允许抗体表位相互作用。最常见的表位检索方法是热诱导的表位检索(HIER),其利用温度,pH和时间的组合来轻轻地去除交叉桥并暴露感兴趣的抗原。

Once the antigen has been exposed for investigation, the following general steps (fig. 2) are followed:

Fig. 2: IHC General Steps
  • 封锁- 不是感兴趣的蛋白质和内源性过氧化物酶的蛋白质的反应位点可以产生假阳性信号。为了避免这种情况,利用多个阻塞步骤来避免非特异性绑定。
  • 检测- 抗体介导的检测通过荧光或色原型方法实现。直接荧光检测(图3)涉及使用与荧光团缀合的一抗体。为了检测未充分表达的抗原,间接荧光检测(图3)通过使用荧光团缀合的二抗来放大信号。用酶 - 缀合的二抗和形成组织上的底物进行色原检测。
Fig. 3: IHC Indirect Detection and Direct Detection Diagram**
  • Counterstain- 这些化学污渍用于帮助鉴定细胞特征(例如具有血管基碱和DAPI的细胞核),以及在阳性抗体染色和一般细胞器染色之间产生对比。
  • 成像- 用于数据比较,定性分析和抗原的基本可视化的显微镜。在Covance,我们利用Aperio Versa扫描仪允许更详细地细节和精细检测在非常低的水平(图4)。
图4 f:扁桃体)KI67积极核,b)AE1/AE3+5D3 cytoplasmic staining on Mouse Skin, c) EGFR positive staining on placenta, d) HER2 positive cytoplasm on BT474 tumor, e) PR positive nuclei on BT474 tumor, f) AE1/AE3+5D3 on epithelium of mouse tongue

IHC has proven to be an invaluable assay in the areas of research and drug discovery. We stay up to date on the most valuable techniques, detection, and analysis to best meet your needs. If you would like to learn more about how we can help support your study through Immunohistochemistry, pleasecontact us这样我们就可以为您讨论最佳选择。

Additional Resources:
查看我们的IHC手册
查看我们验证的IHC标记


*插图信用:https://www.nationaldiagnostics.com/histology/article/aldehyde-fixaives

**插图信用:http://www.leicabiosystems.com/pathologyLeaders/an-animated-guide-to-immunohistochemisty/

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