三种固定液对Feulgen反应显示DNA的比较

<正>本实验用10%福尔马林(10%FA),FAA液(甲醛、95%酒精、冰醋酸按10:85:4体积比)及Carnoy氏液作为固定液,对一个月SD大鼠睾丸组织(约3mm~2/块)进行固定.制得5μm的切片后,分别用Felugen反应显示DNA和H—E染色法染切片,并对Feulgen染色切片中的糖原细胞用图象分析仪进行DNA定量测定.结果发现:(1)选择60个左右大小、染色深浅均相近的精原细胞进行图象分析,用平均光密度值进行比较.发现Carnoy固定的切片,其均值最大而变异系数(CV)最小;10%FAA固定的居中,FAA固定的切片均值最小而CV最大.在镜下观察中,发现10%FA及FAA液固定后的切片染色均匀而Carnoy所染切片中曲细精管着色深浅不一.所以我们认为,(1)用10%FA作固定液对DNA的定量分析较适合.(2)对细胞核及细胞质的形态而言,经FAA液和Carnoy氏液固定的组织,其染色效果较由10%FA固定的组织好.经 FAA液和Carnoy氏液固定的切片,低倍镜下可见曲精小管管腔内初级精母细胞的丝状染色体及其他细胞的颗粒状染色质,高倍镜下核的结构更加清晰.而经10%FA固定的组织切片,低倍镜下管腔内的各级生精细胞的胞核呈现均匀成片的紫红色,观察不到丝状染色体,高倍镜下仔细分辨,才可隐约见到.但因Carnoy氏液固定的组织块脆性大,不易切片,所以FAA液固定最适于形态观察.     

Urocortin在人足月胎盘合体滋养细胞表达的亚细胞定位

目的: 利用冰冻超薄切片免疫电镜技术, 观察研究urocortin在人足月胎盘合体滋养细胞上的表达与亚细胞定位。方法: 取材5例足月胎盘组织块固定在4%多聚甲醛液中, 每例标本分成两部分, 一部分做常规石蜡包埋切片, 免疫组化染色, 光镜下观察; 另一部分做冰冻超薄切片, A蛋白-金免疫标记, 透射电镜下观察。 结果: (1) 光镜下观察可见: urocortin主要分布在足月胎盘合体滋养细胞的胞质内。(2) 免疫电镜下观察可见: 抗urocortin金颗粒主要见于合体滋养细胞的粗面内质网上, 也见于细胞核膜上和细胞核内。结论: 足月胎盘的合体滋养细胞能合成和分泌urocortin, urocortin在胞质内合成后可内化（internalization）入胞核内, 提示人胎盘上作为肽类激素的urocortin可能存在“胞内分泌（intracrine）”现象。     

微波二次固定提高肿瘤组织冰冻切片及苏木素—伊红染色质量的研究

冰冻切片质量的好坏直接关系到能否准确及时地作出病理诊断,以指导手术治疗方式,近年来,国内外学者对如何提高冻冻切片及染色质量做了大量工作,但仍然存在着组织结构被冰晶破坏,对比染色差,细胞核着色不清晰等缺点,我们应用微波加热固定液对组织块进行预固定,切片后再次固定的“二次固定技术”处理肿瘤组织,获得了比单纯脱脂固定切片更好的效果.1 材料与方法1.1 材料 选用我院1994～1995年外科送检需要急诊冰冻的乳腺、胃、肠、卵巢、甲状腺及脑等处的肿瘤组织,取材2cm×1.5cm×0.5cm数块.YWY781A型医用微波炉为浙江临安爱迪电子仪器厂产品,有8个功率选择开关,最大输出功率为500W.1.2 方法(1)将肿瘤组织分为不处理和处理组,处理组分别用生理盐水,10%甲醛和Bouin液在80℃恒温水浴固定5min,用微波2档(输出功率250W)固定1min.(2)将上述肿瘤组织用恒冷切片机切成5μm厚的冰冻切片数张,贴片稍于后分成不固定组和固定组,固定组分别用酒精-冰醋酸-甲醛固定液(AAF).改良的     

用无水乙醇做快速固定液在冰冻切片中的应用

冰冻制片的最大优点是快速,但由于快速固定、快速制片,常因制片质量问题造成诊断误差。冰冻切片固定很主要,若固定不良,细胞肿大、核变形、破裂,可造成假阳性或假阴性。过去我们应用的AAF和Cardon这两种固定液,常有细胞肿大现象和核着色不良现象,为解决此问题,我们从1991年9月开始经反复试验,发现用无水乙醇做冰冻切片     

大鼠未固定神经组织DiI荧光示踪方法的研究

目的用DiI荧光示踪剂对大鼠未固定神经组织染色,观察神经组织在冰冻保存条件下DiI的示踪效果,以及扩散距离和扩散时间,从而获得使用DiI示踪未固定神经组织的良好方法。方法大鼠脑和脊髓组织取材,放置在-20℃条件下冰冻,用DiI标准溶液表面涂布小脑皮质或脊髓断端,保持-20℃冰冻,染色达到一定时间后用多聚甲醛固定液固定组织,以阻断DiI的传导,冰冻切片观察。结果大鼠未固定神经组织冰冻后,DiI扩散速度较快,均可见顺向。逆向示踪显示,神经元胞体及突起染色效果良好。结论大鼠未固定神经组织在离体后冰冻保存较用固定液保存,其DiI扩散速度明显加快。     

介绍一种FAAPT冷冻切片快速固定液

手术中冷冻切片的病理诊断是根据冷冻切片组织学形态来进行 ,以确定病变组织的良恶性为目的〔1〕。制作冷冻切片包括制片、固定、染色三个环节 ,在冷冻切片中固定液的选择是不可忽视的一个因素。我们在工作中经反复试验在众多固定液中选择ＦＡＡ液 (福尔马林 -醋酸 -乙醇 ) ,经改良配成一种适合于冷冻切片的ＦＡＡＰＴ(福尔马林 -醋酸 -乙醇 -苦味酸 -ＴｒｉｔｏｎＸ - 10 0 )快速固定液。该液具有固定速度快、渗透力强、ＨＥ染色鲜艳、组织结构清晰等优点。1　材料与方法1 1　ＦＡＡＰＴ固定液的配制　福尔马林 15ｍｌ,醋酸 3ｍｌ,95 %乙醇…     

大鼠视网膜标本石蜡切片的固定方法

目的探讨制备大鼠视网膜石蜡切片的固定方法。方法将大鼠眼球固定于4%多聚甲醛(PFA)和不同浓度(1%、5%、10%、20%)甲醇组成的混和固定液中并制成石蜡切片,经HE染色后在显微镜下观察。结果经4%PFA+不同浓度甲醇固定的眼球外形均无明显变形和收缩。用添加1%和5%甲醇固定液固定的标本未见明显的视网膜脱离,而用添加10%和20%甲醇固定液的眼球的周边部视网膜出现轻度脱离。显微镜下视网膜组织结构完整清晰,各层细胞排列紧密,无明显裂隙,染色鲜艳。相反,采用福尔马林固定的视网膜发生严重脱离。结论 4%PFA+甲醇的固定方法即可保持视网膜结构完整,无脱离,又能提高抗原保存性,效果优于福尔马林固定液,是适合大鼠眼球,尤其是视网膜固定的一种有效方法。     

优化人胃癌细胞SGC-7901细胞骨架图像的激光共聚焦显微技术

目的利用激光共聚焦技术,对比三种固定液不同固定时间对胃癌细胞系SGC-7901的细胞骨架荧光染色的影响。方法选择三种常用固定液:2.5%戊二醛,4%多聚甲醛及95%乙醇,对接种24h后的SGC-7901细胞分别进行10min,20min及30min等不同时间点固定,5%BSA(含0.2%Triton X-100)封闭透膜1h,荧光抗体FITC标记的鬼笔环肽37℃避光孵育2h,DAPI室温染核15min,激光共聚焦扫描显微镜扫描,对比观察其染色结果。结果三种固定液及不同固定时间对SGC-7901细胞骨架染色效果不尽相同。95%乙醇固定后微丝之间区分不明,排列混乱,无网状结构,染色效果与固定时长无关。2.5%戊二醛固定后微丝结构完整,但层次不清晰。4%多聚甲醛固定后微丝结构完整,层次清晰,固定20min及30min微丝荧光染色清晰。结论 4%多聚甲醛固定20min对细胞骨架固定效果最好,荧光染色标记结果为后续细胞骨架功能研究优化实验方法并提供理论依据。     

一种新冰冻切片制片方法

冰冻切片制片技术的优劣不同程度地影响快速病理诊断水平。我们在工作中发现,切出的冰冻切片略微吹干后,经30s福尔马林处理及5s乙醇处理,再进行HE染色,其镜下观察效果与石蜡切片较为接近。 1 材料和方法 半导体冰冻切片机,HE染色液及福尔马林等。对下述三种方法制得的冰冻切片进行比较。 1.1 新鲜组织置冰冻切片机切片,贴于载玻     

单宁酸—氯化铁法媒染肾上腺血管的观察

用２％多聚甲醛、２％戊二醛、２％单宁酸配制的媒染固定液灌流大鼠，取肾上腺做冰冻切片放入２—３％氯化铁溶液中呈色，成功地显示了肾上腺皮质、髓质血窦的形貌。高倍镜下可见血窦呈空心管道状，其管壁为细纤维丝状结构编织而成，具有较强立体感。     

比较4种不同复合固定液对小鼠视网膜的固定效果

背景：在各种实验与临床病理研究中,需要一种能够较好固定视网膜并且避免固定液性视网膜脱离的眼球固定液。 目的：比较4种不同复合固定液对小鼠视网膜的固定效果。 方法：40只昆明小鼠处死后,立即摘除眼球,并将其随机分为4组,每组20只眼球。分别浸泡在固定液1 (多聚甲醛4 g,加入0.1 mol/L磷酸缓冲液80 mL,加热至60 ℃左右,持续搅拌,使粉末完全溶解,加少许1 mol/ L NaOH 澄清。待冷却后,加冰醋酸5 mL、丙酮10 mL,用0.1 mol/L磷酸缓冲液补足至100 mL),固定液2(5%重铬酸钾40 mL、体积分数为10%甲醛10 mL、冰醋酸10 mL、三氯醋酸10 mL、10%醋酸钠10 mL);固定液3(冰醋酸10 mL、体积分数为40%甲醛溶液20 mL、生理盐水70 mL、体积分数为75%乙醇10 mL混合);固定液4(无水乙醇60 mL、体积分数为40%甲醛溶液10 mL、冰醋酸10 mL、氯仿20 mL)。固定24 h进行常规脱水、石蜡包埋固定、苏木精-伊红染色。 结果与结论：经过固定液4固定的视网膜组织可以清晰看到视网膜各层,而且罕见固定液性视网膜脱离。由于固定液4中加入能与乙醇、冰醋酸互溶的氯仿,有效地促进了固定液的眼球渗透,故降低了固定液性视网膜脱离,效果比其他几种固定液好。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Assessment of oestrogen receptor content of breast carcinoma by immunohistochemical techniques on fixed and frozen tissue and by biochemical ligand binding assay.

The oestrogen receptor content of 61 breast carcinomas was assessed by biochemical ligand binding assay and three immunohistochemical techniques--a frozen section method (Abbott ER-ICA) and on paraffin wax sections after fixation by two methods. The two fixatives used were Carson's buffered formalin and methacarn, and a DNAse pretreatment of sections was used. Overall agreement for the immunohistochemical methods with the ligand binding technique were 95%, 85%, and 86% for the frozen, formalin, and methacarn methods, respectively. A semiquantitative staining score was performed and all three methods gave significant correlations of staining scores with biochemical ligand binding values. The frozen section method was best (r = 0.88) with the fixed tissue methods yielding poorer correlation coefficients. Several factors affected staining, including the nature of the fixative and variable activity of DNAse. It is concluded that immunohistochemical assessment of oestrogen receptor content on fixed tissue provides acceptable qualitative information but that standardisation of protocols for tissue processing will be necessary for optimal utility and especially for quantitative assessments.     

Effects of different fixatives on staining patterns of four lectins in cultured microvascular endothelial cells

Fixatives have significant influence on lectin histochemistry of tissue sections; however, their roles in lectin fluorescent staining of cultured cells remain unclear. In this study, using cultured microvascular endothelial cells (MVECs) from rat intestinal mucosa, the effects of seven fixatives on the fluorescent staining patterns of four lectins were investigated. The results indicated that every fixative gave concanavalin A (Con A) and wheat germ agglutinin (WGA) strong positive staining in different patterns. When fixed with Zenker’s, periodate–lysine–paraformaldehyde (PLP), 2·5% glutaraldehyde (GA), and 4% paraformaldehyde (PFA) solution, the cell membranes and cytoplasms stained, and the fluorescence in the cell edges was brighter. Rossman’s solution, 95% ethanol, and acetone fixation caused cytoplasmic staining, while the fluorescence was weak and evanescent when using acetone. Dolichos biflorus agglutinin (DBA) and Ulex europaeus agglutinin I (UEA I) were stained; revealing very faint fluorescence in cytoplasms just when PLP and 2·5% GA solution were used. In conclusion, this study shows that fixatives have significant effects on the fluorescent staining of MVECs. Fixatives containing aldehydes and mercury chloride are better options for cell membrane glycans, and those containing ethanol for cytoplasmic ones. Acetone fixation is not suitable for lectin histochemistry.     

Immunohistochemical demonstration of c-erbB-2 oncoprotein in gastric adenocarcinoma: comparison of cryostat and paraffin wax sections and effect of fixation.

AIMS--To investigate the effects of fixation on the immunohistochemical demonstration of c-erbB-2 oncoprotein using paraffin wax and cryostat sections; to compare c-erbB-2 expression in non-neoplastic and neoplastic gastric tissues. METHODS--Adjacent blocks of tumour and non-neoplastic tissue from four gastrectomy specimens were put into a panel of 10 fixatives including acetone, B5, Bouin's fluid, Carnoy's fluid, buffered formalin, formol dichromate, zinc formalin, 4% paraformaldehyde, periodate-lysine-paraformaldehyde (PLP) and periodate-lysine-paraformaldehyde-dichromate (PLPD) before embedding in paraffin wax for sectioning. Similar tissue blocks were snap frozen and cryostat sections were postfixed in these fixatives, either alone or in combination, before immunostaining. RESULTS--In paraffin wax embedded sections the best fixative was PLP, and in frozen tissues the best results were obtained after fixation of cryostat sections in buffered formalin followed by cold methanol and acetone. Applying these fixatives to samples from a further 16 gastrectomy specimens, strong membrane staining of c-erbB-2 protein was found in the tumour in eight of 16 cases (50%) using paraffin wax sections, and staining was stronger in the better differentiated carcinomas. For frozen tissues, positive membrane staining was found in all gastric adenocarcinomas, but differential staining intensity associated with tumour differentiation could not be detected. CONCLUSIONS--These results indicate that fixation and paraffin wax embedding affect the results of immunohistochemical demonstration of c-erbB-2 in gastric cancer. The choice of fixative is critical in the demonstration and evaluation of c-erbB-2 protein expression by immunohistochemistry in gastric carcinomas. Staining results also vary depending on whether frozen or paraffin wax embedded tissues are studied.     

The sensitivity and specificity of various peroxidase stains--the difference between DAB and 3AC stainings]

FAB Cooperative Group has cited 3 or higher percentage in the peroxidase (PO) activity as one of criteria for the diagnosis of acute myeloid leukemia. We have previously reported in two cases of acute myelomonocytic leukemia (M4) that there was a great difference between 3,3'-diaminobenzidine (DAB) and 3-amino 9-ethyl carbazole (3AC) as substrates for PO reaction. In order to confirm the previous result, we extended the cases and compared the PO activities in blood films taken from several leukemic subjects, which were fixed with various kinds of fixatives, using DAB and 3AC as substrates. Their peroxidase activities were also determined through electron microscopy (EM-PO). There were no differences among fixatives and substrates in staining normal granulocytic cells (neutrophils and monocytes) and cells in 13 cases of leukemia, except for two cases, one with M4 and the other with relapse of M2. These showed the highest PO activity with 3AC staining and 10% formaldehyde acetone buffer for fixation. Besides, all types manifested the highest positivity in EM-PO, except for the relapse of M2 that showed a higher positivity in the peroxidase stain by 3AC staining, 10% formaldehyde acetone buffer fixation than the EM-PO. Unlike other leukemic blasts PO reaction products of blast cells of the two cases showed a scattered distribution of microscopic granules. These findings suggested the difference, which was seen in the previous reports, of the PO stain between two substrates might be due not only to sensitivity for staining but to the presence of some heterogeneity such as isoenzyme in the myeloperoxidase.     

The effect of fixation and trypsinization on the immunohistochemical demonstration of intracellular immunoglobulin in paraffin embedded material

Using an indirect labelled immunoperoxidase technique the influence of fixation time on the antigenicity of intracellular immunoglobulin in lymphoid tissue fixed in buffered formalin has been investigated. Within a fixation period of 96 hours a decrease of 15% of stainable immunoglobulin containing cells was found, for every 24 hours the fixation time was prolonged. By comparing sections from tissue fixed in buffered formalin and selected fixatives (Lillie's AAF, Bouin's fluid, Clarke's fluid and 96% ethanol 1% acetic acid (E--A) processed at 4 degrees C and at 25 degrees C) an increased number of stained immunoglobulin containing cells was found in tissue fixed in Lillie's AAF, Bouin's fluid, Clarke's fluid and E--A processed at 4 degrees C. No difference was found between tissue fixed in buffered formalin and E--A processed at 25 degrees C. In addition the effect of pretreatment of the sections with trypsin on the number of stainable immunoglobulin containing cells was investigated. Trypsinization of sections from formalin fixed material increased the number of stainable cells substantially. No essential effect was seen on tissue fixed in Lillie's AAF and Bouin's fluid. In contrast trypsin treatment of sections from tissue fixed in Clarke's fluid and E--A completely destroyed the tissue. No differences were observed between different immunoglobulin classes examined as regards the effect of fixation time, fixatives and trypsinization.     

Human intestinal mucosal mast cells: evaluation of fixation and staining techniques

The staining properties of tissue mast cells are influenced by the method of fixation. Differences in fixation and staining techniques may explain the contradictory results in the published reports on the number of human mucosal mast cells (MMC) in the gastrointestinal mucosa in health and disease. We have examined the influence of fixatives on the staining properties of human MMC in operative biopsy specimens of human jejunum. Specimens were divided into pieces, each of which was fixed in one of the following fixatives: Carnoy's, basic lead acetate (BLA), Baker's, Bouin's, isotonic formol-acetic-acid (IFAA), 10% neutral buffered formalin, formol sublimate, and formol saline. Thereafter, tissues were paraffin-embedded and 5 micron sections were cut and stained with either astra-blue/safranin pH 0.3, or toluidine blue pH 0.5. Counts of the number of MMC/mm2 were obtained for each fixation method. The results show a critical influence of the fixative on the number of mast cells identified after staining. For example with astra-blue/safranin the mean MMC/mm2 count was 40 in formol-saline-fixed specimens, and 268 in Carnoy's-fixed specimens. In biopsies fixed with formalin-based fixatives, mast cells were more readily stained with toluidine blue. It is recommended that Carnoy's or BLA be used as the fixative for any light microscopic study of human MMC.     

An evaluation of potentially suitable fixatives for immunoperoxidase staining of estrogen receptors in imprints and frozen sections of breast carcinoma

The estrogen receptor (ER) content of breast carcinoma is generally accepted as valuable in predicting clinical outcome and tumour response to hormonal manipulation. We applied a new immunocytochemical assay for estrogen receptors (Abbott ERICA Monoclonal) to 20 breast tumours, and examined the efficacy of 16 fixation procedures before immunoperoxidase staining of frozen sections and imprint preparations. Our findings indicate that the fixatives of choice are periodatelysine-paraformaldehyde at 22 degrees C, or 10% formalin followed by acetone at -10 degrees C. These fixation procedures are simpler, less time-consuming, and provide superior staining, tumour cytomorphology and higher ER values than the 3-reagent sequence recommended by Abbott Laboratories. There was a significant correlation between the ER scores in the frozen sections and the imprints. Positive ER cytosol results correlated with the staining index in the frozen sections, and the ER scores in the imprints. We conclude that imprints are suitable preparations for ER analysis by the immunoperoxidase technique, particularly for small tumour specimens.