FineFix固定液与福尔马林固定液对组织保存及固定的比较

随着石蜡切片、免疫组化、特殊染色以及分子遗传学分析在病理诊断上的普遍应用,对标本组织处理要求越来越严格.固定是标本处理过程中的重要环节,如果固定液选择不当、浓度不均、固定时间与温度不合适以及固定液过少等均会使组织固定不良而影响制片质量、免疫标记及分子生物学检测结果,从而影响病理诊断.福尔马林是一种有毒、致敏及致癌物,废液处理成本较高,经其固定的组织抗原蛋白的氨基与醛基交联形成羧甲基封闭抗原决定簇,使免疫组化着色效果减弱[1].本实验采用FineFix固定液(以下简称FF)与福尔马林液固定的组织进行对比,经FF固定的组织形态结构完整,尤其在提取DNA和RNA的质和量上具有明显的优越性[2].     

经福尔马林固定后羊肠风干标本的制作

制作胃肠风干标本通常用新鲜器官经水洗出内容物后要置于２％石碳酸溶液内浸泡１～２小时,或在３～５％福尔马林溶液中固定２～３天,然后再吹气、风干。如果在未水洗之前就已固定,则给水洗内容物造成困难（尤其是羊肠,因较细）,原因是标本经福尔马林固定后变硬、失去弹性、管腔变小。在管道一端注水冲洗时,使管腔内容物堆积到一起,堵塞管腔,使内容物无法洗出。几年来,我们利用经福尔马林固定教学实习后的羊肠,采取一些相应的补救措施,制作出了几件比较理想的风干标本。１取材利用经福尔马林灌注固定教学实习后的羊肠,外形完整,…     

微波辐射固定和微波辐射与甲醛结合固定动物组织方法

利用微波辐射固定组织和微波辐射与固定液结合固定组织的报道已有不少[1-4],但多是某一具体方法的报道,而很少对在利用微波辐射固定组织中起决定作用的因素进行探讨,也很少有对微波辐射与固定液结合固定组织的方法进行全面性探讨。为此,我们进行了微波辐射固定动物组织和微波辐     

福尔马林固定后层粘连蛋白受体抗原活性的恢复

常规福尔马林固定，石蜡包埋后，使组织内许多有意义抗原的抗原活性减弱。消失而很难检测到。最近，许多实验室证明用微波辐射能使一些抗夺的有所恢复。以往我们在福尔马林固定，石蜡包进组织中未能染出层粘连蛋白受体。     

福尔马林固定废弃尸体标本的骨骼处理及福尔马林的回收

经福尔马林固定后的尸体使用后"解剖废弃物"处理是一件比较剌手的事,通过对国内医学院校近60家解剖学实验室调查,均是用焚化法和掩埋法处理废弃物[1-2].     

对福尔马林固定剂相关理论的再认识

福尔马林是组织病理学技术常规应用的组织固定剂,传统组织病理学技术理论[1-6]普遍认为:40%甲醛水溶液为福尔马林,40%甲醛水溶液是饱和溶液,40%浓度时甲醛主要由聚合形式构成,4%浓度时甲醛主要由单体形式构成,甲醛水溶液久存易自行分解形成白色副醛沉淀可过滤后使用,出现三聚甲醛沉淀物表示已变性不宜使用等.本文基于基础化学理论知识,总结了福尔马林固定剂相关理论的新认识.     

微波固定组织对超微结构影响的电镜观察

目的：观察微波照射固定对组织细胞器结构的影响，方法：将大鼠肝组织分别浸泡在生理盐水、０．２５％戊二醛、２．５％戊二醛、５戊二醛液体中，按不同时间进行微波照射固定后，常规制片，电镜观察。结果：ＭＩ时间≤２０ｓ，液体的温度≤２５℃，肝细胞内各有形成分均有一煊膨胀。ＭＩ时间≥６０ｓ，液体的温度≥４５℃时，肝细胞内各有形成分不同程度破坏，其中戊二醛各组较生理盐水组严重，且戊二醛组中，戊二醛浓度越高，对细胞     

单纯微波固定在组织制片中的应用

在组织制片过程中,组织的正确固定具有重要意义,适当而完好的固定是优良组织切片的基础,特别在免疫组化染色时尤为重要。良好的固定能保存细胞内的物质接近其生活状态时的形态和位置,尽量减少抗原成分弥散或丢失,以保证染色的特异性及敏感性。在临床病理及科研工作中,又常需要我们在短时间内制作出高质量的切片,为此笔者尝试利用微波技术进行组织固定,探索单纯微波固定在组织制片中的应用,以期缩短制片时间,提高制片染色质量。     

福尔马林固定后的尸体骨标本制作方法

<正>骨标本在人体解剖学的学习中是最先接触的人体标本,良好、优质的骨标本能激发学生的学习兴趣和激情。教学的骨标本主要来源于:一是未经福尔马林固定尸体的     

The Role of Microwave Radiation in Reducing Formaldehyde Fixation Times Demonstrated in Liver

Abstract

Turnaround time is an important consideration in surgical pathology. The critical step in processing, formaldehyde fixation, is the longest single step. Attempts to shorten the process either by underfixation or by heating have not been satisfactory primarily because the resulting poor-quality fixation impairs immunohistochemistry. The current study evaluated the quality of microwave radiation as an energy source when the fixation time is shortened. Electron micrographs, immunohistochemistry, and hematoxylin and eosin-stained paraffin sections were used to evaluate fixation quality relative to the standard 24-h fixation time. By optimizing and controlling the processing variables temperature and wattage during microwave irradiation, we demonstrated that microwave energy alone can reduce fixation times to as little as 20 min while maintaining the quality as judged by ultrastructural, immunohistochemistry, and hematoxylin and eosin criteria.     

Formalin fixation and immunoreactivity in prostate cancer and benign prostatic tissues

Jaraj SJ, Egevad L. Formalin fixation and immunoreactivity in prostate cancer and benign prostatic tissue. APMIS 2010; 118: 383–8. For better fixation, formalin injection of radical prostatectomy (RP) specimens has been suggested. We aimed to assess its effect on immunoreactivity using immunohistochemistry (IHC). A tissue microarray of cancer and benign tissues from 42 RP specimens was constructed. Twenty‐one of the prostates had been injected with formalin prior to formalin immersion. IHC staining was performed using 15 antibodies, including nuclear and cytoplasmic markers known to be positive in prostate tissue: pan cytokeratin, P504S, high molecular weight (HMW) keratin, PSA, vimentin, actin HHF35, thioredoxin‐1, peroxiredoxin‐2, PDX‐1, BAX, p27, androgen receptor (AR) and heat shock proteins (HSP) 27, 60 and 70. Differences in staining intensity in cancer and benign tissues were compared separately except for HMW keratin. Only 7 of 29 analyses showed significant differences between groups, including 5 of 15 antibodies. The expression of AR and HSP 27 was stronger in formalin‐injected tissue, while the opposite was true for HSP 60, HSP 70 and peroxiredoxin‐2. For most antibodies, formalin injection does not significantly affect immunoreactivity in prostate tissue. The staining variability caused by inter‐ and intratumoral heterogeneity may be greater than that caused by the fixation method.     

Value of Formalin Fixation for the Prolonged Preservation of Rodent Myocardial Microanatomical Organization: Evidence by MR Diffusion Tensor Imaging

Previous ex vivo diffusion tensor imaging (DTI) studies on formalin‐fixed myocardial tissue assumed that, after some initial changes in the first 48 hr since the start of fixation, DTI parameters remain stable over time. Prolonged preservation of cardiac tissue in formalin prior to imaging has been seen many times in the DTI literature as it is considered orderly. Our objective is to define the effects of the prolonged cardiac tissue exposure to formalin on tissue microanatomical organization, as this is assessed by DTI parameters. DTI experiments were conducted on eight excised rodent hearts that were fixed by immersion in formalin. The samples were randomly divided into two equinumerous groups corresponding to shorter (～2 weeks) and more prolonged (～6–8 weeks) durations of tissue exposure to formalin prior to imaging. We found that when the duration of cardiac tissue exposure to formalin before imaging increased, water diffusion became less restricted, helix angle (HA) histograms flattened out and exhibited heavier tails (even though the classic HA transmural variation was preserved), and a significant loss of inter‐voxel primary diffusion orientation integrity was introduced. The prolonged preservation of cardiac tissue in formalin profoundly affected its microstructural organization, as this was assessed by DTI parameters. The accurate interpretation of diffusivity profiles necessitates awareness of the pitfalls of prolonged cardiac tissue exposure duration to formalin. The acquired knowledge works to the advantage of a proper experimental design of DTI studies of fixed hearts. Anat Rec, 299:878–887, 2016. © 2016 Wiley Periodicals, Inc.     

Fixation of cells in tissue culture by microwave irradiation

Summary A novel method employing in situ microwave fixation for cells cultured in monolayer is described. This method, which avoids the cell loss associated with chemical fixation, is useful for cells intended for immunofluorescence studies, for prefixation of cells for electron microscopy, and for other situations requiring cell fixation.     

微波解冻法对冷冻组织细胞角蛋白免疫组化检测影响的实验研究

目的：揭示微波解冻对冻结组织免疫组化染色效果的影响,为用微波解冻冷冻组织进行免疫组化染色提供实验依据。方法：将清洁级大耳白家兔分为常规对照组、自然解冻组、温水解冻组、微波解冻组。用空气将家兔栓塞致死后取其肝、肺、肾组织,包埋并制成切片,进行广谱细胞角蛋白免疫组化染色并观察染色结果。结果：微波解冻对肝、肾、肺冻结组织中细胞角蛋白抗原的影响不明显,均能正常显色。结论：冻结组织微波解冻对细胞角蛋白的免疫组化检查未见明显不良影响,提示温和的微波解冻对组织中细胞角蛋白抗原影响不明显。     

Rapid Immunofluorescence Staining by Microwave Incubation in Patients with IgA Nephropathy

Abstract

The effect of microwave incubation on the immunofluorescence staining findings in renal tissues in patients with IgA nephropathy is described. Ten patients with IgA nephropathy were examined. The renal sections were incubated with FITC-labeled rabbit anti-human IgA, IgM, IgG, or C3 antisera in a microwave oven that was operated at 2,450 MHz with an output of 500 W. There was no significant difference in the distribution of IgA or C3 deposition in the glomeruli between incubation in the microwave for 3–7 sec and 4°C overnight incubation. However, the immunofluorescence intensity of IgA after microwave incubation was less than that after incubation at 37°C for 1 min to 2 hr or 4°C overnight incubation. The intensity or distribution of IgG and IgM deposition in the glomeruli was markedly less after microwave incubation than that after incubation of 4°C overnight. We conclude that rapid immunofluorescence by microwave incubation is useful in the examination of renal biopsy specimens, especially IgA and C3 staining findings in patients with IgA nephropathy. (The J Histotechnol 13:175, 1990)     

Aberrant CD45 (Leukocyte Common Antigen) Staining of Non-Malignant Breast Lesions in Zinc Formalin Fixed Tissue

Abstract

Leukocyte common antigen (LCA/T200/CD45) has been considered an antigenic epitope expressed only on the cytoplasmic surface membrane of nucleated hematopoietic cells. This study describes the expression of LCA on the surface membrane of mammary ductal cells in specimens of fibrocystic disease and fibroadenoma. The reaction appeared specific and is most likely due to unexpected antigenic epitope expression of LCA in these tissues. (The J Histotechnol 16:151, 1993)     

Glyoxal Fixation and Its Relationship to Immunohistochemistry

Abstract

Glyoxal is a popular substitute for formalin and in many ways acts like it, although there are significant differences. When formulated correctly, glyoxal fixatives produce superior morphological detail in only 1-9 h, but crosslinking does not occur. Glyoxal has a unique reactivity with arginine, producing a cyclic imidazole in place of the highly charged guanidinium group, thus reducing eosinophilia in arginine-rich tissue elements. In the absence of crosslink-induced masking of epitopes, most antibodies work directly on glyoxal-fixed specimens without the need for antigen retrieval. The arginine reaction does cause loss of immunoreactivity in arginine-rich antigens, however. Fortunately, the imidazole is readily removed by a simple antigen retrieval process: pH 8.6 Tris HCl buffer for 10 min at 125°C. The conformational basis for needing antigen retrieval, and how it works on a molecular level is explained for both glyoxal and formalin fixation. (The J Histotechnol 29:65, 2006)

Submitted November 4, 2005; accepted with revisions March 15, 2006.     

Effects of Tissue Fixation on the Inhibition of Erythrocyte Pseudoperoxidase Activity in Immunoperoxidase Methods

Abstract

Incomplete inhibition of erythrocyte pseudoperoxidase activity during immunoperoxidase techniques can cause falsepositive results and produce problems in data interpretation. Here, we examined the relationship between tissue fixation method and the frequency of false-positive results. Mouse brain tissues were immersed in 10% neutral-buffered formalin, 10% formalin, or 100% ethanol for 1 d, 3 d, 1 week, or 2 weeks. After treatment with hydrogen peroxide to block endogenous peroxidase activity, paraffin-embedded sections were immunostained for glial fibrillary acidic protein. False-positive results were observed when sections were fixed with 10% formalin or 100% ethanol for 1 d to 2 weeks but not when sections were fixed with 10% neutral-buffered formalin for durations of 1 week or less. Moreover, the intensity of false-positive results was positively associated with increased duration of fixation. Together, these results indicate that the incidence of false-positive results depends on the type of fixative and the duration of fixation. Fixation with 10% neutral-buffered formalin within 1 week may help to minimize these false-positive results. We also examined the efficacy of Kardasewitsch's method for inactivating pseudoperoxidase activity. This method, however, does not seem to be applicable to immunohistochemistry (The J Histotechnol 31(4):165–168, 2008).

Submitted July 14, 2008; accepted with revisions July 26, 2008     

The Case for Perfusion Fixation of Large Tissue Samples for Ultrastructural Pathology

We present the case for the perfusion fixation of large, freshly isolated tissue samples of liver and lung from dog, rat, and mouse. Individual lobes of liver and lung were fixed by vascular perfusion using a technique that is simple and quick to perform and results in a reproducibly high standard of ultra-structural preservation compared to immersion fixation. A major advantage to the use of this technique lies in the ability to provide tissue samples for diagnostic ultrastructural pathology and toxico logical pathology while avoiding the need for whole-organ or whole-body perfusion fixation. This advantage therefore permits the use of fresh tissue from the same organ for other investigative purposes (e.g., drug metabolism studies and pharma cokinetics), thereby allowing correlation of structure and function. The advantages of perfusion fixation compared to immersion fixation are discussed, and potential applications for tissue preparation of postmortem specimens and also for scanning electron microscopy are indicated.