毕业论文乙醇和异丙醇对程序降温冷冻盒温度变化的影响25583.doc

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1、 本科毕业论文(设计) 题 目: 乙醇和异丙醇对程序降温冷冻盒温度变化的影响 学 生: 学号: 学 院: 生命科学学院 专业: 生物科学 入学时间: 2009 年 9 月 1 日指导教师: 屈长青 职称: 教授 完成日期: 2013 年 5 月 9 日乙醇和异丙醇对程序降温盒温度变化的影响 摘 要:传统的梯度降温冷冻方法对细胞的损伤严重,细胞复苏后成活率低,活力差。程序降温法降温速度较缓,对细胞的损伤小,保存的长期性和安全性均可得到保障。细胞的体外长期保存一般采用10%二甲基亚砜低温保护剂, 程序降温后贮存在液氮中。但传统的程序降温法需要购置昂贵的程序冷冻仪,因此,程序降温冷冻保存难以在多数实

2、验室中进行推广。现制作一种简易的程序降温盒,以实现便捷经济地程序降温。通过分析寻找出乙醇和异丙醇可作为程序降温液,本实验通过对比乙醇和异丙醇以及乙醇和异丙醇1:1的混合液的温度变化速率,得出乙醇和异丙醇的混合液的降温速率慢,最适宜作程序降温液。 关键词:程序降温盒; 乙醇; 异丙醇; 温度变化Effect of ethanol and isopropanol on programmed cooling box temperatureAbstract: Freezing method of ladder often use of todays cooling on cell damage, th

3、e low survival rate of cells after resuscitation, poor activity. Using the method of program cooling speed is slow, has small damage to the cells. The long-term preservation and safety can be guaranteed. The long-term preservation of cells in vitro by cryoprotective agent 10% two dimethyl sulfoxide,

4、 programmed cooling after storage in liquid nitrogen, but the traditional programmed cooling method requires the purchase of expensive program freezing equipment, therefore, the programmed cooling cryopreservation is difficult to spread in most laboratories. We are looking for a cooling speed slow s

5、olution, design program cooling box, to realize quick economic programmed cooling. Through the analysis to find out the more suitable for ethanol and isopropanol, through the contrast of ethanol and isopropyl alcohol and their 1:1 mixture temperature change rate, we get that the ethanol and isopropa

6、nol mixture significantly slower cooling rate.Key words: programmed cooling box ;ethylalcohol;isopropanol;temperature shift目 录1. 引言(绪论).12.材料与方法.22.1 实验材料.22.1.1 试剂.22.1.2 主要仪器和设备.22.2 实验方法.22.2.1制作程序冷冻盒.22.2.1.1寻找合适的材料. .22.2.1.2制作冷冻管的固定板.22.2.2程序降温液.22.2.2.1 程序降温液的筛选.22.2.2.2程序降温液的处理.22.2.3 测量温度变化

7、.32.2.4 实验结果观察.33.实验结果.33.1 不同材质的对比.33.2 程序降温液的筛选.33.3 比较三种溶液的温度变化.34.结论(结束语).4参考文献.5致谢 .61 引言 随着生物科技的迅速发展,细胞越来越多应用于生物实验中。细胞冻存是用于细胞保存的主要方法之一。利用冻存的技术将细胞置于-70冰箱中低温保存1,可以使细胞暂时脱离生长状态,从而将其细胞特性保存起来,在需要的时候再复苏细胞用于实验。而且适度地保存一定量的细胞,可以防止因正在培养的细胞被污染或其他意外事件而使细胞丢种,对细胞保种起到了的作用。除此之外,还可以利用细胞冻存的形式来购买、寄赠、交换或是运送某些细胞。 细

8、胞冻存主要有两种方法:一是阶段降温法,利用冷存管处于4、 -20、 -80保存2;二是程序降温法,利用程序降温盒设定程序由室温降低至-70,最后再放置到液氮槽中进行长期保存。降温速率对细胞的保存效果非常重要3。常规分段降温耗时较长。温度降低过快容易对细胞造成“胞内冰损伤”4。细胞冻存通常采用慢冻速溶的方法来减少细胞损伤5。因为如果降温过快,会导致细胞内外水迅速结晶化,从而导致细胞的结构破坏、PH改变、蛋白质变性等不良的后果,就会对细胞造成损害。而慢冻能使细胞缓慢失水,以减少胞内结晶的形成进而保护细胞。复苏时让细胞快速融化是为了防止在融化过程中已经融解了的水渗透入细胞而导致的二次结晶对细胞形成损

9、害6。利用程序降温法,相对于传统的冻存方法能实现缓慢降温,大大减少了细胞在冷冻过程中的损伤,提高复苏成活率7。但传统的程序降温法需要购买昂贵的程序降温仪,成本大幅度提高8。而制作程序降温盒可以解决这一难题。程序降温盒的设计就是基于某种液体的比热容大随外界温度变化慢的原理,使被冻存的细胞实现缓慢降温。程序降温盒的使用方法:向程序降温盒中添加100ml左右的程序降温液,再将准备冻存的细胞管置于程序降温盒内的固定板上。最后将程序降温盒直接放入-70冰箱即可。如需长期保存再转放入液氮中。图1.简易的程序降温盒本实验通过对比异丙醇,乙醇及它们1:1的混合液降温速度,发现混合液的降温速度最适宜,变温速度约

10、在12/min。混合液的降温速度明显慢于纯的异丙醇或乙醇。2. 材料与方法2.1 实验材料2.1.1 试剂异丙醇,乙醇。 2.1.2 主要仪器、设备-100100数显温度计 (误差范围在1) ,自制程序降温盒,超低温冰箱。2.2 实验方法2.2.1 制作程序冷冻盒2.2.1.1 寻找合适的材料 分别把普通塑料瓶、特种塑料和一块小泡沫置于-70冰箱一夜后取出。观察材料形态特质是否发生改变,并拍照记录。2.2.1.2 制作冷冻管的固定板本实验使用的冷冻管固定板的材料是泡沫板。将泡沫板切割成厚约0.5cm,直径等于程序冷冻盒的圆板状。再根据冷冻管的大小在泡沫板上切割出8个圆孔,每个圆孔之间相间分布,

11、保持适当间隔以保证牢固。最后将泡沫板置于程序冷冻盒内固定。2.2.2 程序降温液2.2.2.1 程序降温液的选择 通过查找比热容较高的液体进行比较,选出比热容较大的几种纯溶液。如水、甲醇、异丙醇、乙醇的比热容较高,分别是4.19、2.5、2.5、2.43 J/(kgK)。甲醇易挥发,在空气中易燃易爆,因而不能选择甲醇。水的熔点高,在0以下即凝固,凝固后体积变大因而也不能选择水作程序降温液。而异丙醇和乙醇的凝固点较低,在-70不会凝固。因此选择异丙醇、乙醇及异丙醇和乙醇的混合液(体积比为1:1)作为实验对象。2.2.2.2 程序降温液 分别将盛有100ml的异丙醇,100ml乙醇,100ml异丙

12、醇与乙醇1:1的混合液的程序冷冻盒置于-70冰箱中5h。2.2.3 测量温度变化 首先将数显温度计置于-70冰箱,使其显示温度与冰箱温度相同,以减小误差。再迅速从冰箱中取出程序冷冻盒,将温度计的感应端置于程序冷冻盒的溶液中,读出初始温度并开始计时。每过一分钟记一次温度。当温度上升到0时温度变化很慢,停止记录。重复上一步骤。再测另外两种溶液温度变化,每分钟重复两次作为对比求平均值以减小误差。2.2.4 实验结果观察观察结果,记录数据,拍照。整理分析数据,并绘制折线图,以便清晰反映数据的变化情况。3. 结果与分析3.1 不同材质的对比 图2. 普通塑料瓶放在-70冰箱一夜后 图3. 特种塑料瓶放在

13、-70冰箱一夜后由图1、图2可知,普通塑料瓶子在-70冰箱里存放一夜后发生严重的变形,而特种塑料形态完好。因此选择特种塑料盒子作为程序冷冻盒的盒子。3.2 程序降温液的筛选100ml异丙醇,100ml乙醇,100ml异丙醇与乙醇一比一的混合液。3.3 比较三种溶液的温度变化 图4. 乙醇、异丙醇及乙醇和异丙醇的混合液随温度变化3结论与讨论细胞在冷冻过程中,会因为降温速率过快导致在复苏时裂解,死亡或是丧失活性。细胞冻存通常采用慢冻速溶的方法来减少细胞损伤。利用程序降温法,使细胞处在一个循序渐进的降温过程中,尽可能保证细胞在冷冻过程中不受损伤9。传统的程序降温法需要购买昂贵的程序降温仪,实验过程费

14、时,需要购买设备多10,花费太大,占空间。而此实验设计的程序冷冻盒操作简便,体积小,价格低廉。程序降温盒的设计就是基于某种液体的比热容大随外界温度变化慢的原理,使被冻存的细胞实现缓慢降温。比热容是单位质量的某种物质升高单位温度所需的热量,比热容越大,物质随环境温度变化越慢。乙醇的比热容为2.43 J/(kgK),异丙醇的比热容为2.5 J/(kgK),乙醇的比热容比异丙醇的略小。本实验通过测量得到乙醇和异丙醇温度变化相似,在乙醇和异丙醇的温度从-70升到-30的过程中,温度上升的平均速度约为2.35/min;温度从-30上升到0的过程中,温度上升的平均速度约为1.15/min。乙醇和异丙醇的混

15、合液温度的变化速度相对较慢,在温度从-70上升到-300的过程中,温度上升的平均速度为2/min,在温度从-30升到0的过程,温度上升的平均速度约为0.94/min。由此可知在整个过程中,乙醇和异丙醇的温变速率的范围在13/min,相对来说,乙醇的温变速率稍快一些。异丙醇与乙醇混合液的温变速率的范围是0.92/min,比单独的乙醇和异丙醇温度下降的要慢。已知大多数细胞在冻存的过程中,降温的速度在12/min时,细胞的损伤最小,因此对于大多数细胞,选择酒精和异丙醇的混合液作为程序降温液保存细胞效果最好。参考文献:1 张浩,毛秉智,董波,等. 利用低温冰箱进行细胞长期保存的研究Q. (军事医学学院

16、放射医学研究所),北京: 生物学杂志,2002, 18 (1): 29-30.2 李力施,李力复,霍燕琼. 细胞冻存时缓慢降温的简易方法(广州动植物检疫所), 中国兽医科技,1990,(2):22-23.3 杨腾飞,丛笑倩,程启康,等. 人胚胎肝细胞程序降温保存实验研究, 实验生物学报 2005, 38(3): 247-251.4 王秀美,考桂兰,侯先志,等. 白花奶牛乳腺上皮细胞冻存方法的研究, 畜牧与饲料科学, 2011,32(9-10):65-67.5 王东,谢琴,何存利,等. 4种细胞冻存法的比较(宁夏农林科技畜牧兽医研究所),宁夏农林科技1997,(2):53-55.6 王英丽,于鸿

17、,张健. 不同种类细胞培养和冻存方法的改进(吉林省肿瘤防治研究所), 使用肿瘤学杂志 ,1998,12 (1): 12-13.7 王晶,李亚里,闫志风,等. 人胚胎干细胞的保存方法, 中国组织工程研究与临床康复, 2008,12 (12) 2291-2295.8 史曦凯,张翼军. 外周血干细胞的程序降温保存E (第三军医大学西南医院血液科),重庆: 重庆医学,2003,32 (5).9 沈华萍 丁春梅 迟占有 不同降温速率对脐血干细胞冷冻复苏后生物学特性的影响R 生物工程学报, 2003, 22 (4) 280-281.10 赵仁彬,张爱玲,陆 洁. 超低温冰箱转液氮阶梯降温法与传统程序降温法

18、保存造血干细胞的比较, 中国组织工程研究与临床康复, 2011,15 (19) . 致 谢在毕业论文即将完成之际,收获颇多,感触良深。论文完成的背后离不开可爱的亲们的支持和帮助。首先我要感谢我的指导老师屈长青老师,屈老师严谨细致、一丝不苟的作风是我在人生路上的榜样。他在论文的选题以及实验方面给予了我无私的帮助,在忙碌的教学工作中抽出时间来审查我的论文,指出其中的不足,并不耐其烦的指导我进行论文的修改,在此特向屈老师表示我由衷的感谢;其次感谢姬云涛老师,刘小丽和杨京霞老师,谢谢你们在实验过程中诸多方面给予我的指导,教会我科学的严谨态度和永不言弃的精神;也要感谢实验室和我一起做实验的“战友们”,我

19、们一起走过大学最后的日子,在一次次“预实验”的失败之后,我们不断完善着自己,虽然忙碌但却很快乐;同时还要感谢09级生科二班的兄弟姐妹们,谢谢你们曾经给予我的关心和帮助,我们满怀希望,我们一腔热情,我们是一个可爱的大家庭。在这到处充溢着感伤的季节,在这离别的时刻,我心中满是不舍,但我想说“海内存知己,天涯若比邻”,我们不曾离开!待添加的隐藏文字内容2还有我宿舍的姐妹们,感谢你们大学四年的帮助,在我最悲伤的时候安慰我,在我最无助的时候支持我,快乐的时候我们一起疯狂,烦恼的时候我们一块分担,是你们给了我温暖,让我感受到“家”的温馨;最后要我要感谢我亲爱的父母,感谢你们的养育之恩,你们是我力量的源泉,

20、永恒的动力! 大学四年即将结束,回头望去,有欢笑,有泪水,有遗憾,有感动我们一起携手走过这最为可贵的四年,最为难忘的四年。曾经,我们年少轻狂;现在,我们日渐成熟,我们都在经历华丽的“蜕变”。大学,虽然不尽完美,但却让我们学会更加珍惜,学会勇于追求自己想要的生活! Employment tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if: you dont agree with the disciplin

21、ary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, seeDismissal.You can make a claim to an employment tribunal, even if you haventappealedagainst the disciplinary ac

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25、organisations listed underFurther help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. This is known as adamages-based agreement. In England and Wales, your solicitor cant charge

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27、ind your nearest CAB, including those that give advice by e-mail, click onnearest CAB.For more information about making a claim to an employment tribunal, seeEmployment tribunals.The (lack of) air up there Watch mCayman Islands-based Webb, the head of Fifas anti-racism taskforce, is in London for th

28、e Football Associations 150th anniversary celebrations and will attend Citys Premier League match at Chelsea on Sunday.I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport.For me its about how he felt and I would like to speak to him first to find out what hi

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31、lf the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字开头的年龄已经到了尾声。或许是愧疚于自己似乎把转瞬即逝的很多个不同的日子过成了同一天

32、的样子;或许是追溯过去,对自己那些近乎偏执的怪异信念的醒悟,这些天以来,思绪一直很凌乱,在脑海中不断纠缠。总觉得自己自己似乎应该去做点什么,或者写点什么。二十年的人生轨迹深深浅浅,突然就感觉到有些事情,非做不可了。The end of our life, and can meet many things really do?而穷尽我们的一生,又能遇到多少事情是真正地非做不可?During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the ag

33、e, will be more and more found that those things are optional; Junior high school, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; Then in high scho

34、ol, think dont want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found h

35、imself has already cant remember his appearance.童年时,觉得压岁钱和新衣服是过年必备,但是随着年龄的推进,会越来越发现,那些东西根本就可有可无;初中时,以为要有一场暗恋才意味着真正的成长,但三年过去后,自己心平气和的写同学录的时候,突然就发现是不是真正的成长了,好像并没有那么重要了;然后到了高中,觉得非要吐露出自己的心声才能为高中生涯里的懵懂情愫划上一个句点,但毕业晚会的时候最终还是被梗塞在了咽喉,后来再次站在他曾经挥汗如雨的球场,看着他投过篮球的球框时,突然间发现自己已经想不起他的容颜。Originally, this world, can p

36、roduce a chemical reaction to an event, in addition to resolutely, have to do, and time.原来,这个世界上,对某个事件能产生化学反应的,除了非做不可的坚决,还有,时间。A persons time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more

37、 often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一个人的时候,自己的想法总是特别地清晰。想要的,不想要的,界限明确,好

38、像没有什么可以撼动自己。也曾经好像已经下定了决心去做某件事,但更多的时候是最后又打起了退堂鼓。嫌恶过自己的怯懦,最终却发现有很多缘分,有很多错过,好像冥冥之中真的已经注定。那些曾经所谓的非做不可,只是青葱年华里自己给自己注射的一支强心剂,或者说,是自以为是的精神寄托罢了。At the moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt; Those were broken into various shapes of stationery

39、; From the corner at the beginning of deep friendship; Have declared the end of the encounter that havent start planning. Those years, those days of do, finally, like youth, will end in our life.此刻,天空是阴暗的,空气里有着刚下过雨之后的清新因子。突然想到那件蓝格子衬衫;那些被折成各种各样形状的信纸;那段从街角深巷伊始的友谊;还有那场还没有开始就宣告了终结的邂逅计划那些年那些天的非做不可,终于和青春一

40、样,都将在我们的人生中谢幕。Baumgartner the disappointing news: Mission aborted. r plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move thro

41、ugh the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. A

42、s he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.The supersonic descent could happen as early as Sunda.The weatheThe balloon will slowly drift to the edge of space at 120,000 feet ( Then, I would assume, he will slowly step out onto something resembling an Oly

43、mpic diving platform.Below, the Earth becomes the concrete bottom of a swimming pool that he wants to land on, but not too hard. Still, hell be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound - 690 mph (1,110 kph) - in less than 40 seconds. Like hit

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