小鼠卵巢组织的超速冻存法研究

目的　本实验通过对小鼠卵巢组织进行冻存研究 ,掌握卵巢的低温生物学特性 ,摸索出一种简便有效的组织器官冻存法 ,为卵巢移植及器官冷冻提供有用的技术方法。方法　通过对小鼠卵巢组织进行慢速程序法与快速液氮蒸汽法冻存 ,比较分析了不同方法所需保护剂种类、浓度、渗透平衡时间。采用对解冻后卵巢组织超微结构观察、组织化学染色、激素测定及自体、异体移植后动情期的恢复作为评价指标。结果与结论　通过上述实验表明用同种冷冻保护剂 ,液氮蒸汽法冻存的卵巢组织超微结构保存良好 ;组织化学染色示其活性与程序法冻存组织相同 ;自体、异体移植后 ,小鼠动情周期的恢复率及血清雌二醇水平各项指标均与慢速程序法冷冻无显著性差异     

乳猪肝细胞短期培养后的低温保存

本文对乳猪肝细胞短期培养后冻存法和直接冻存法进行比较。采用改良原位两步胶原酶灌注法分离乳猪肝细胞,将肝细胞接种到含10％DMSO、激素、生长因子和10％NBS的RPM1 1640培养基中,用阶段性冻存法保存肝细胞,分别对直接冻存和培养后冻存10天、20天复苏的肝细胞进行培养,动态观察其活率和功能。研究结果表明各组复苏后的肝细胞均保持较高的活率;短期培养后冻存组肝细胞活率、G-6-Pase活性、白蛋白和葡萄糖合成功能及安定转化能力均较直接冻存组为高;LDH活性低于直接冻存组;冻存时间的长短对其白蛋白、尿素和葡萄糖合成功能有一定影响。因此,短期培养后冻存法较直接冻存法为好。     

加热洗脱硝酸纤维膜上保存的尿蛋白质

用膜保存尿蛋白质对于生物标志物的研发意义重大,从保存尿蛋白质的硝酸纤维膜上洗脱蛋白质的有效性,决定着保存方法被接受的程度和应用的范围。加热洗脱蛋白质的方法,通过提高硝酸纤维膜溶解时的温度等方式;并运用SDS-PAGE和LC-MS/MS分析加热洗脱方法所制备的尿蛋白质样品,将其与强烈涡旋洗脱方法和直接丙酮沉淀方法所制备的尿蛋白质样品比较。结果显示,加热洗脱方法比强烈涡旋洗脱方法获得更多的蛋白质(P0.05),且蛋白质无降解;加热洗脱方法和直接丙酮沉淀方法制备的蛋白质样品,质谱所鉴定到蛋白质重叠率无明显差异(分别是92.6%、96.8%),蛋白质丰度CV值20%的蛋白质占总蛋白质的比例均很高(分别是85.2%、94.4%)。加热洗脱法具有很好的技术重复性,操作更加高效、简单,有利于用膜保存尿蛋白质方法的推广应用。     

美洲鲥雄性生殖细胞冷冻保存及移植

采用分离细胞冻存和组织块直接冻存2种方法, 进行美洲鲥(American shad, Alosa sapidissima)精巢细胞的长时间冷冻保存(>250d), 并比较分析2种不同冻存方法对美洲鲥雄性生殖细胞的冻存效果。解冻复苏后用Hochest33342和PI共染细胞核, 分析统计各期雄性生殖细胞的存活率, 结果显示组织块冻存方法所得精原干细胞和精母细胞的存活率明显高于分离细胞冻存的; 而精细胞及其他细胞存活率在2种方法间无显著差异; 特别是, 镜检发现组织块冻存方法所得精子存活率高达93.83%, 说明此冻存方法能同时高效地冻存美洲鲥各期生殖细胞, 包括成熟的精子。同时, 将组织块冻存的美洲鲥生殖细胞用PKH26染色标记后移植到出苗第1天的斑马鱼仔鱼中, 在细胞植入后5d仍能在受体中检测到供体细胞, 且有部分供体细胞能与内源生殖细胞共定位, 表明经过长时间冷冻保存的美洲鲥生殖细胞仍具有生殖细胞特性, 且能整合到斑马鱼受体性腺原基。研究结果为进一步开展美洲鲥, 或其他洄游性鱼类的生殖细胞发育、培养及种质资源保存等研究工作奠定了技术理论基础。     

切花百合离体茎尖玻璃化法超低温保存研究

以切花百合西伯利亚试管苗离体茎尖为试材,通过正交设计试验对预培养培养基中蔗糖浓度、预培养时间和PVS2处理时间等影响超低温保存存活率的主要因素进行了分析,初步建立了切花百合种质玻璃化法超低温保存的技术方案。通过形态观察、可溶性蛋白和同工酶检测,冻存前后材料的遗传稳定性没有发生改变,表明该方法对切花百合的种质保存具有较强的实用意义。     

包埋玻璃化法超低温保存植物种质的研究进展

包埋玻璃化法是在玻璃化法和包埋脱水法基础上发展起来的超低温保存植物种质的新技术。它具有能同时处理大量材料,处理后恢复生长快,对材料的毒害作用较小及成芽率高等优点,已成功地用于辣根、山嵛菜等20余种植物,在植物种质资源的保存上显示出了巨大的应用潜力。本文介绍了包埋玻璃化法产生的背景及其优点, 阐述了包埋玻璃化法的基本方法和预培养、包埋、脱水、化冻及恢复培养等过程,比较了该法冻存后的效果和冻存后所形成植株的遗传稳定性,同时指出了进一步研究的重点。     

光镊捕获的单个解冻人血红细胞的拉曼光谱研究

红细胞的冰冻与解冻的实施为血液的长期保存提供了有效的方法。在过去的几十年中,红细胞冻存有过数种方法,其中高甘油冻存法比较普遍,因而用此方法保存红细胞是否对红细胞产生了影响及产生了什么影响是值得研究的。作者利用激光光镊拉曼光谱系统,通过拉曼光谱对冻存人血红细胞进行研究;结果显示,红细胞冻存前后的拉曼光谱有一定的变化,解冻提取后也产生了一定的变化,这些变化主要体现在对应拉曼光谱的位置和强度上。研究结果对进一步研究红细胞的冻存具有一定的参考价值。     

包埋玻璃化法超低温保存植物种质的研究进展

包埋玻璃化法是在玻璃化法和包埋脱水法基础上发展起来的超低温保存植物种质的新技术.它具有能同时处理大量材料,处理后恢复生长快,对材料的毒害作用较小及成芽率高等优点,已成功地用于辣根、山嵛菜等20余种植物,在植物种质资源的保存上显示出了巨大的应用潜力.本文介绍了包埋玻璃化法产生的背景及其优点,阐述了包埋玻璃化法的基本方法和预培养、包埋、脱水、化冻及恢复培养等过程,比较了该法冻存后的效果和冻存后所形成植株的遗传稳定性,同时指出了进一步研究的重点.     

斑马鱼精子冻存与复苏实验方法与流程

斑马鱼是研究胚胎发育及其遗传机制的重要模式脊椎动物。目前人们已经积累了大量的突变体和转基因鱼系, 如何安全、妥善地长期保存这些品系是每一个研究斑马鱼的实验室都会面临的问题。精子冻存与复苏技术是目前最为简单有效的一种长期保存斑马鱼遗传品系的方法。应用这一技术不仅可以节省大量的鱼房空间与人力、物力, 使鱼系的使用与保存更加灵活和持久, 更重要的是能够防止珍贵鱼系的意外丢失, 为鱼系保种提供额外的保障。这类方法一般是通过体外挤出精子或研磨精巢获取新鲜的精子, 用适量的冻存液混匀后, 分装保存在液氮罐中。需要时可以随时通过体外授精的方法使精子复苏。经过30年的发展, 随着冷冻保护剂的不断改良和冻存与复苏条件的不断优化, 斑马鱼精子冻存与复苏技术已逐渐成熟。文章简单回顾了斑马鱼精子冻存与复苏技术的历史与发展, 并重点介绍本实验室自2005年以来常规使用的斑马鱼精子冻存与复苏的方法及具体流程。
补充资料 ：冻存与复苏实验指南 [视频]     

人体蠕形螨的DNA提取与随机引物PCR检测

【目的】探索人体毛囊蠕形螨和皮脂蠕形螨DNA的提取方法。【方法】采用液氮反复冻融研磨法破碎螨体细胞, 选用改良小昆虫DNA提取法、碱裂解法和试剂盒提取法, 分别提取冻存时间在5个月内和8~10个月的毛囊蠕形螨和皮脂蠕形螨基因组DNA, 并用随机引物PCR方法进行检测。【结果】蛋白核酸测定仪检测结果显示, 试剂盒法提取的DNA纯度较高、量较多, 明显优于改良小昆虫法和碱裂解法。随机引物扩增结果显示清晰的DNA指纹图谱, 两种人体蠕形螨DNA指纹具有明显差异。蠕形螨冻存时间影响DNA提取的量, 但对DNA提取的纯度和RAPD指纹图谱影响较小。不同DNA提取方法提取的同一种蠕形螨DNA指纹图谱基本相似, 试剂盒法和改良小昆虫法提取的DNA样本条带多而清晰, 碱裂解法提取的样本条带少而模糊。【结论】液氮反复冻融研磨法破碎蠕形螨细胞是有效的, 蠕形螨冻存时间不宜超过6个月, 试剂盒提取法是提取蠕形螨DNA的好方法。RAPD技术可以用于这两种人体蠕形螨DNA分子水平上的检测和分类。     

不同保存方法对川金丝猴粪便DNA提取效果的影响

目的:川金丝猴(Rhinopithecus roxellana)是我国特有珍稀物种,其粪便作为一种非损伤性样品,为珍稀濒危动物的种群数量调查、遗传多样性评价、亲缘关系、系统进化等研究带来了很大便利,本研究试图建立高效、简便的粪便样品保存方法。方法:在现有珍稀濒危动物粪便样品保存方法的基础上,分别使用干燥法、冷冻法和干燥-冷冻法保存川金丝猴的粪便样品,比较了不同保存方法的DNA提取效果,以及对mtDNA控制区片段的PCR扩增成功率和微卫星基因的PCR扩增效率。结果:干燥法、冷冻法和干燥-冷冻法三种不同保存方法保存粪便1周时间后,提取的粪便DNA样本扩增mtDNA片段的成功率均为92%,微卫星基因的扩增成功率分别为79%、78%、80%;保存2个月后,mtDNA片段扩增成功率分别为80%、76%和80%,微卫星基因扩增成功率分别为65%、61%、67%;保存6个月后,mtDNA片段扩增成功率分别为56%、52%和64%,微卫星基因扩增成功率分别40%、34%、46%。因此,随着保存时间的增长,三种方法的保存效率都将明显降低,但干燥-冷冻法得到的DNA样本扩增成功率相对较高。结论:粪便样品能够为川金丝猴的遗传多样性评价等相关研究提供有效信息,干燥-冷冻法保存能够更为有效的保证DNA的提取和基因扩增效率。     

沼气高产菌群保藏条件的比较

目的：利用不同方法对沼气高产菌群进行保藏,比较各方法不同时间的保藏效果。方法：应用液体低温冷藏法、液体石蜡封存法、液氮冷冻保藏法和低温冷冻干燥保藏法保藏的菌种,分别在保藏后1个月、3个月、6个月及1年后复苏菌种,测定其产气速度、产气量。结果：以上几种方法均能够保证所保藏菌群在1个月内得到复苏并产气,低温冷冻干燥法及液氮冷冻法保藏沼气产生菌菌群可达1年以上,产气速度、产气量较为理想,优于液体低温冷藏法及液体石蜡法。     

硝酸纤维膜和丙酮沉淀尿蛋白质保存方法的比较

硝酸纤维膜法是一种简单、快速、经济的尿液蛋白质保存方法,但其与传统尿液蛋白质丙酮沉淀方法的差异有待进一步研究。相同尿液分别经硝酸纤维膜法和丙酮沉淀法制备尿蛋白质,经液相串联质谱分析鉴定蛋白质,采用谱图数定量,研究两种不同方法的差别。结果显示硝酸纤维膜法和丙酮沉淀法鉴定蛋白质数目几乎相同,鉴定蛋白质在谱图数的分布上几乎相同,鉴定蛋白质在蛋白质变异系数的分布上也几乎相同。因此,硝酸纤维膜法处理尿蛋白质与丙酮沉淀法基本一致,可以应用于大规模临床尿液样本的保存。     

Enrichment of the basic/cationic urinary proteome using ion exchange chromatography and batch adsorption

Anionic or acidic proteins are the main compositions of normal urinary proteome. Efforts to characterize human urinary proteome, thus, have focused mainly on the anionic compartment. The information of cationic or basic proteins present in the normal urine is virtually unknown. In the present study, we applied different methods to enrich cationic urinary proteome. Efficacies of these methods were compared using equal volume (1 L) of urine samples from the same pool obtained from 8 normal healthy individuals. Cation exchange chromatography using RESOURCE-S column provided the least amount of the recovered proteins, whereas batch adsorption using SP Sepharose 4 Fast Flow beads equilibrated with acetic acid (pH 4.8) provided the greatest yield of protein recovery. The recovered proteins were then resolved with 2-DE (pI 7-11) and identified by peptide mass fingerprinting using MALDI-TOF MS. There were several isoforms of immunoglobulin heavy and light chains enriched by these methods. In addition, three isoforms of interferon alpha-3 (IFNalpha3) and six isoforms of eosinophil-derived neurotoxin (EDN), were also enriched. The enrichment of IFNalpha3 and EDN was particularly effective by batch adsorption using SP Sepharose 4 Fast Flow beads equilibrated with acetic acid (pH 6.0). Initial depletion of anionic components using DEAE batch adsorption reduced the recovery yield of these two proteins and did not improve recovery of any other cationic urinary proteins. We conclude that batch adsorption using SP Sepharose Fast Flow beads equilibrated with acetic acid (pH 6.0) is the method of choice to examine the basic/cationic urinary proteome, as this protocol provided the satisfactory yield of protein recovery and provided the greatest amount as well as maximal number of IFNalpha3 and EDN isoforms. Our data will be useful for further highly focused study targeting on cationic/basic urinary proteins. Moreover, the techniques described herein may be applicable for enrichment of cationic proteomes in other body fluids, cells, and tissues.     

The cryopreservation of fish thymocytes and its potential application for immunological reconstitution experiments

Fish thymocytes were cryopreserved by two methods, a programmed freezing method by a direct control system and a mechanical freezing method. There was no loss of viability or ability to respond to Concanavalin A compared to control thymocytes, up to 5 months after cryopreservation, and no difference between the two methods.     

Comparison of cryopreservation methods for the long term storage of the marine diatom Haslea ostrearia (simonsen)

Long term maintenance of microalgal strains by serial subculturing is often expensive and time-consuming. Alternative methods, such as cryopreservation, present several benefits and thus seem more relevant. Our study aimed at comparing two cryopreservation procedures applied to the marine diatom Haslea ostrearia (Simonsen): (1) a two-step freezing method in liquid media using 5%, 10% and 20% MeOH, Me₂SO or Glycerol, and (2) an immobilization-dehydration method consisting in an algal cell entrapped in 0.7 M sucrose dehydrated and air-flow desiccated calcium alginate beads before “direct” or “two-step” freezing. Our results showed that the cryopreservation of H. ostrearia was feasible. With the two-step freezing protocol only Me₂SO maintained cell viability without contamination but the low percentage of viability (<10%) prevents its use. Conversely, the immobilization-dehydration methods tested in this study were effective. Average viability of 57% and 77% were obtained with the “direct” and the “two step” cooling assays respectively, ensuring preservation of the genetic traits of H. ostrearia.     

Impact of tissue preservation on collagen fiber architecture

Microarchitectural features of collagen-rich extracellular matrices provide the mechanical foundation for tissue function and exhibit topographical cues that influence cellular behavior including proliferation, migration and protein expression. Preservation of tissue microarchitecture is required for accurate evaluation of tissue characteristics and pathology. It is unclear whether common tissue preservation methods possess equal ability to preserve microarchitecture. We investigated collagen microarchitecture in samples that had been flash frozen, fixed in formalin or preserved in RNAlater®, and which contained both collagen-rich and collagen-sparse regions. Fibrillar collagen organization was characterized using picrosirius red staining and second harmonic generation (SHG) microscopy. Maintenance of collagen fiber characteristics compared to the gold standard of flash freezing depended on both the method of preservation and the local collagen content of the tissue. Both formalin fixation and RNAlater® preserved collagen fiber characteristics similar to flash freezing in collagen-rich areas of the tissue, but not in collagen-sparse regions. Analysis using picrosirius red staining indicated preservation-dependent changes in overall tissue architecture and suprafibrillar organization. Together with considerations of cost, ease of use, storage conditions and ability to use the preserved tissue for RNA or protein analysis, our quantitative characterization of the effects of preservation method on collagen microarchitecture may help investigators select the most appropriate preservation approach for their needs.     

Different methods of tissue preparation for X-ray microanalysis combined with scanning electron microscopy based on zebra fish, Brachydanio rerio muscle fibres

Four preparation methods for electron probe X-ray microanalysis (EPXMA) of muscle fibres were compared: (1) dissection, freezing in LN2 (liquid nitrogen), cutting in cryostat, freeze-drying and analysis; (2) dissection, immersing in Tissue-Tek, freezing in LN2, cutting in cryostat, the following steps as in method 1; (3) dissection, freezing in LN2, freeze-drying, separation of fibres into groups; (4) dissection, cutting into 2 mm thick slices by razor blade, freezing in LN2, following steps as in method 1. The contents of Na, Cl, and K as well as K/Na, Cl/K, ratios were taken as criteria of good preservation of muscle fibres. The best results were obtained by method 1. Good morphological preservation can be routinely observed in sections prepared by methods 3 and 4. However, the diffusible elements and K/Na, Cl/K ratios were not retained at relatively constant level among the individual samples. Fibres prepared by methods 1 and 3 showed, despite of freezing artefacts, high K/Na, and low Cl/K ratio. After method 1, high level of the elemental contents was retained, and it did not differ significantly among the samples, showing relatively low standard deviation values.     

Processing of ovine cardiac valve allografts: 1. Effects of preservation method on structure and mechanical properties.

It is essential to have some method of preservation of allograft valves during the time between procurement and implantation. Cryopreservation is the most commonly-used storage method today but it has the major disadvantage of high cost, and because its aim is to preserve living cells only relatively gentle antimicrobial treatments are used. This study addresses two interrelated questions: Is it necessary to maintain living donor cells in the tissue graft?Can more effective measures be used to reduce the risk of transmission of diseases, especially viral diseases, via human tissue grafts. In this paper, were port an investigation of four preservation methods that could be combined with more effective disinfection: cryopreservation with dimethyl sulphoxide, storage at ～4 °C in a high concentration of glycerol as used for the preservation of skin, snap-freezing by immersion in liquid nitrogen and vitrification. Snap freezing was mechanically damaging and vitrification proved to be impracticable but two methods, cryopreservation and storage in 85%glycerol, were judged worthy of further study. Cryopreservation was shown to maintain cellular viability and excellent microscopic structure with unchangedmechanical properties. The glycerol-preserved valves did not contain any living cells but the connective tissue matrix and mechanical properties were well preserved. The importance of living cells in allograft valves is uncertain. If living cells are unimportant then either method could be combined with more effective disinfection methods: in that case the simplicity and economy of the glycerol method would be advantageous. These questions are addressed in the two later papers in this series.