抗原修复方法在乙肝肾免疫组化检测的应用

乙型肝炎病毒相关肾小球肾炎（HBVAssciated Glomerulne phvitis）,简称乙肝性肾炎,临床上常要求对肾穿刺乙肝肾患者的标本做乙肝表面抗原（HBsAg）,乙肝核心抗原（HBcAg）或乙肝e抗原（HBeAg）检测。然而不同的抗原修复方法对肾穿组织石蜡切片HBsAg、     

不同抗原修复免疫组织化学技术在HPV应用中的比较

许多研究已证实 ,人类乳头状病毒 (ＨＰＶ)与宫颈癌及癌前病变有关。通过ＤＮＡ序列分析鉴定 ,感染人子宫颈的ＨＰＶ亚型有 6、 11、 16、 18、 31、 33、 35、 39和 42 ,其中 6和 11亚型与宫颈尖锐湿疣发病有关 ,16和 18亚型与宫颈癌关系最密切。通常检查的方法是免疫组化法、聚合酶链反应(ＰＣＲ)和ＨＰＶ -ＤＮＡ原位杂交法。由于免疫组化方法较其他两种方法简单易行 ,因此在日常工作中得到广泛应用 ,但常规石蜡切片法抗原易受固定液的影响 ,用免疫组化法检查时必须通过抗原修复技术方能达到满意的结果。为了提高ＨＰＶ免疫组化法的诊断…     

免疫组织化学中的抗原修复技术

概述了免疫组织化学中固定对组织抗原性的影响,综述了抗原修复的方法及其原理。组织块的大小、固定液的种类、浓度及固定时间的长度都影响组织的抗原性。免疫组织化学实践中常用酶消化法、酸水解法、微波金属盐法、高压锅加热法等修复组织的抗原性。     

抗原修复技术在免疫组织化学中的作用

免疫组织化学是一门免疫学与病理形态学相结合的新兴学科 ,是现代生物医学的一项重要方法学 ,具有操作简单、敏感性高、特异性强等特点 ,已经广泛应用于临床病理及其相关学科的研究之中 [1,2 ] 。目前采用甲醛为常规标本固定剂 ,醛基与组织蛋白质中的氨基形成交联使抗原决定簇被遮蔽 ,从而影响免疫组织化学结果 ,而且这种作用随着固定时间增长而加重 [3 ]。抗原修复技术的出现 ,使得原来许多只能在冰冻切片作免疫组织化学得以在石蜡切片上实现 ,抗原修复技术在免疫组织化学中的作用愈加明显 ,并且对免疫组织化学方法的敏感性起着决定性作用[…     

免疫组织化学中抗原修复的研究进展

组织中抗原性的妥善保存和抗原修复技术与免疫组织化学染色的成败有着十分密切的关系 ,因此如何妥善保存抗原以达到最大限度保留组织的抗原性及如何对抗原加以修复成为做好免疫组化染色的重要步骤。免疫组织化学 (ｉｍｍｕｎｏ ｈｉｓｔｏｃｈｅｍｉｓｔｒｙ) ,简称免疫组化 ,是免疫学与分子生物学技术和形态学相结合的一门学科 ,是用已知抗体 (或抗原 )检测组织细胞中的未知抗原 (或抗体 )的技术 ,具有操作简单、敏感性高、特异性强等优点 ,已广泛用于病理诊断、鉴别诊断及胚胎发育、神经解剖等相关学科的研究。大量实践证明组织中抗原性的…     

有关抗原修复若干问题的探讨

在免疫组织化学反应过程中 ,组织由于固定等方面的问题常导致表达不佳 ,或者假性。为了解决这些问题 ,需要做抗原修复。目前抗原修复的方法较多 ,有真空负压抗原修复法 ,微波辐射抗原修复法 ,高压抗原修复法 ,隔水热抗原修复法和电炉加热抗原修复法。本文根据上述各种方法 ,在实际操作中常可发生的一些问题如 p H的应用范围的选择 ;抗原修复最佳温度的选择 ;有效温度所需要持续的时间 ;抗原修复液必须遵循自然降温的规律 ,否则将达不到抗原修复的目的 ;尽量使用足量的抗原修复液 ;切片必须附贴牢固等。并详细介绍了各种方法的使用过程。在…     

高压消毒蒸锅在石蜡切片免疫组织化学反应抗原恢复中的应用

将石蜡切片浸泡于１ｍｍｏｌ／ＬＥＤＴＡ缓冲液（ｐＨ８．０）中,置入高压消毒蒸锅处理（１２０℃,１０３ｋＰａ）１０ｍｉｎ,以恢复组织中因甲醛固定而被封闭的抗原。结果表明,一些常规免疫组织化学反应呈阴性的组织抗原,经本法处理后呈阳性反应;对不经本法处理即呈阳性的组织抗原,可大大提高第一抗体的稀释度或缩短孵育时间。同微波方法相比,本法可一次处理数百张切片,且对切片和组织的形态无明显损害。因此是石蜡切片免疫组织化学反应组织抗原恢复的理想方法     

微波处理修复抗原后免疫组织化学方法效果的比较研究

冰冻切片经微波处理进行抗原修复后,免疫组织化学方法的敏感性明显提高,显色效果明显增强。提出了冰冻切片在免疫组织化学显色前进行抗原修复的必要性     

不同抗原修复液对免疫组化结果的影响

以热处理来修复抗原是免疫组化(Immuno-histochemistry,IHC)染色中常用的手段,但使用哪种修复液却存在不同的看法,在长期工作实践中,我们发现不同的修复液对有些抗体表达的阳性强度及数量有差异。为此,本实验采用几种不同抗原修复液处理切片进行比较,观察其对IHC染色结果的影响。材料和方法1.材料选择我院外科手术病检乳腺癌标本5例,所有标本均经15%缓冲甲醛液固定,石蜡包埋切片。相同病例的标本切片9张,分别用于三种不同抗原修复液进行ER、PR、BRCA1标记。2.试剂抗体ER、PR、BRCA1及SP试剂盒均为Dako公司产品。3.修复液柠檬酸缓…     

不同抗原修复条件对肠癌MMR蛋白免疫组织化学染色效果的影响

目的 采用3种不同的抗原修复条件对肠癌错配修复(mismatch repair MMR)蛋白进行免疫组织化学染色,从而找到适合本科室的最佳修复条件.方法 回顾性分析近两年工作中遇到的肠癌病例,从中抽取50例,分别进行柠檬酸缓冲液高温高压修复、EDTA缓冲液高温高压修复和CC1缓冲液BenchMark XT机器修复后染色...     

Development of an optimal antigen retrieval protocol for immunohistochemistry of retinoblastoma protein (pRB) in formalin fixed, paraffin sections based on comparison of different methods

A novel protocol for antigen retrieval (AR) for immunohistochemistry (IHC) of retinoblastoma protein (pRB) in formalin fixed, paraffin embedded (FFPE) tissue sections was developed using 0.05% citraconic anhydride as the AR solution for heat treatment based on comparison of different methods. This new protocol has advantages including superior morphological preservation, greater reproducibility, and more intense staining after retrieval. Our study demonstrates the importance of comparing various AR protocols to obtain maximal IHC for standardization and for quantitative IHC.     

Development of an optimal antigen retrieval protocol for immunohistochemistry of retinoblastoma protein (pRB) in formalin fixed,paraffin sections based on comparison of different methods

A novel protocol for antigen retrieval (AR) for immunohistochemistry (IHC) of retinoblastoma protein (pRB) in formalin fixed, paraffin embedded (FFPE) tissue sections was developed using 0.05% citraconic anhydride as the AR solution for heat treatment based on comparison of different methods. This new protocol has advantages including superior morphological preservation, greater reproducibility, and more intense staining after retrieval. Our study demonstrates the importance of comparing various AR protocols to obtain maximal IHC for standardization and for quantitative IHC.     

Hypothesis for the mechanism for heat-induced antigen retrieval occurring on fresh frozen sections without formalin-fixation in immunohistochemistry

The mechanism involved in heat-induced antigen retrieval (AR) remains unproven but probably utilizes the breaking of formalin-induced cross-linkages. We investigated the effectiveness of heat-induced AR on immunohistochemistry and dot-blot analysis using rat uterus tissue sections and protein extracts without formalin-fixation. The unfixed frozen sections, which did not show immunostaining with nine antibodies, were clearly stained after heating the sections. In the dot-blot analysis, the immunoblot sensitivity of detection was greatly enhanced by heating the protein-blotted membrane. These results indicate that other mechanisms of breaking formalin-induced cross-linkages may be present. We propose that one of the other mechanisms for heat-induced AR is that accessibility to the target epitopes of antigenic proteins is limited by natural steric barriers even in the fresh state caused by the antigenic protein itself.     

Standardization in immunohistochemistry: the role of antigen retrieval in molecular morphology

Molecular morphology seeks to integrate the traditional morphologic criteria of surgical pathology with immunohistochemical and in situ hybridization techniques that allow demonstration of a variety of molecules, proteins, RNA and DNA in a tissue section. While immunohistochemistry has proven to be successful for demonstrating lineage related biomarkers of value for diagnosis and classification of tumors, concerns have been raised periodically about validation of reagents, overall reproducibility of the staining method, and interpretation of results. These concerns have been heightened by the burgeoning interest in prognostic markers, where the question extends beyond a relatively simple positive or negative result to an absolute need for quantification of the staining result; not only is it positive, but how much is there? In this presentation at the Annual Meeting of the Biological Stain Commission in June, 2005, I advocate a total test approach that requires systematic attention to pre-analytic, analytic, and post-analytic issues. The approach encompasses all aspects of test performance from specimen acquisition, through fixation, antigen retrieval, processing, staining, interpretation, and reporting of results. A similar systematic approach also may be adopted for in situ hybridization methods, which have performance requirements that in many ways parallel immunohistochemistry.     

Standardization in immunohistochemistry: the role of antigen retrieval in molecular morphology

In performing in situ hybridizations, nonisotopic nucleic acid labeling coupled with colorimetric detection offers a safer, easier and more rapid alternative to using radioactively labeled nucleic acid probes and microscopic autoradiography. Whole mount in situ hybridization is also advantageous, because many samples can be processed identically and the reduced handling of specimens greatly reduces the risk of exposing tissues to RNase(s). The thickness of whole mount specimens, however, often prevents accurate determination of sites of expression within specific tissues. Although post-hybridization embedding and sectioning is a solution to this problem, the precipitate formed following the common colorimetric detection procedure is soluble in the organic solvents used for dehydration prior to embedding. We have developed a dehydration and embedding procedure that takes advantage of the compatibility of L.R. White^® resin containing 10% (v/v) polyethylene glycol 400, and heat polymerized. The addition of the plasticizer allows L.R. White^® embedded tissues to be sectioned at 10 μm providing excellent signal contrast.     

Application of the critical molar concentration concept to heat-mediated antigen retrieval in immunohistochemistry

Previously we have applied Scott's critical molar concentration concept to show that divalent cations, especially Mg²⁺ may be used to measure the affinity of a known monoclonal antibody for its antigen. In this paper we report the application of this same procedure to a study of a series of antigens (three globular proteins and three intermediate filaments). The concept was applied to samples without any previous treatment or after the application of heat-mediated antigen retrieval (using a pressure cooker). Our findings suggest that heat-mediated antigen retrieval sets free protein side-chain(s) that have been masked by formaldehyde fixation. This is reflected in a higher affinity of the antibody for the antigen in question.     

Comparison of estrogen receptor immunocytochemical assay in frozen and paraffin sections.

Frozen and paraffin sections of 11 breast carcinomas were stained for estrogen receptors (ER) using the same rat monoclonal primary antibody, D75P3, as the marker and alkaline phosphatase as the chromogen-linking enzyme. The results of this staining process were assessed visually and with the microTICAS image analysis system to determine the degree of correlation between frozen and paraffin-embedded tissue. In all specimens, some fraction of the nuclei stained positively. This included two specimens selected for their biochemically negative assay; one of them stained strongly positively with D75P3. The results of quantitative analysis support the visually apparent correlation between the two types of samples in terms of both overall staining pattern and intensity of nuclear staining. Although the conclusions of this pilot study are limited because of the small number of cases, this method of staining establishes the feasibility of representative ER determination in archival paraffin-processed material. The additional information provided by this method is potentially useful in stratifying patients in prospective studies on the basis of the efficacy of hormonal therapy in biochemically ER positive breast tumors.     

Application of heat-induced antigen retrieval to aldehyde-fixed fresh frozen sections.

We applied the heat-induced antigen retrieval (HIAR) to aldehyde-fixed fresh frozen sections based on a new approach (i.e., a rapid and complete immobilization of antigen followed by heating). Frozen sections were fixed with 10% formalin in 0.1 M cacodylate buffer (pH 7.4) containing 25 mM CaCl(2) for 30 min, or with 0.5% glutaraldehyde in 0.1 M phosphate buffer (pH 7.4) for 1 min at room temperature, and then autoclaved in 20 mM Tris-HCl buffer (pH 9.0) for 10 min at 120 C. Both fixatives yielded good tissue structure after autoclaving. In the sections fixed with formalin containing CaCl(2), 20 of 22 antigens located in the nucleus, cytoplasm, membranes, and extracellular matrix greatly recovered their antigenicity after autoclaving; only two antigens exhibited stronger immunoreaction in acetone-fixed fresh frozen sections than these sections. Heating also retrieved the immunoreactivity of at least 14 antigens in the sections fixed with glutaraldehyde. We used the similar procedures to localize ligand-free estrogen receptor alpha (ERalpha) and glucocorticoid receptors (GR). Mouse uterine cells exhibited almost the same nuclear ERalpha immunostaining regardless of the hormonal status in glutaraldehyde-fixed fresh frozen sections and unliganded GR was localized mainly in the nucleus of mouse hepatocytes in fresh frozen sections fixed with 20% formalin containing 50 or 75 mM CaCl(2) at 40 C, after autoclaving. These results demonstrate that HIAR is useful for the immunohistochemistry of many antigens in aldehyde-fixed fresh frozen sections.