【正文】 erm preservation and safety can be guaranteed. The longterm preservation of cells in vitro by cryoprotective agent 10% two dimethyl sulfoxide, 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 solution, 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 isopropanol mixture significantly slower cooling rate. Key words: programmed cooling box ； ethylalcohol； isopropanol； temperature shift 3 目 錄 1. 引言（緒論） ..........................................................1 ...........................................................2 實驗材料 ..........................................................2 試劑 ...........................................................2 主要儀器和設(shè)備 .................................................2 實驗方法 ..........................................................2 制作程序冷凍盒 ..................................................2 尋找合適的材料 ................................. .............2 制作冷凍管的固定板 ...........................................2 程序降溫液 ......................................................2 程序降溫液的 篩 選 ............................................2 程序降溫液的處理 .............................................2 測量溫度變化 ...................................................3 實驗結(jié)果觀察 ...................................................3 .............................................................3 不同材質(zhì)的對比 ....................................................3 程序降溫液的篩選 .................................................3 比較三種溶液的溫度變化 ...........................................3 （結(jié)束語） ........................................................4 參考文獻 ..............................................................5 致謝 .................................................................6 4 1 引言 隨著生物科技的迅速發(fā)展，細胞越來越多應(yīng)用于生物實驗中。 程序降溫盒的設(shè)計就是基于某種液體的比熱容大隨外界溫度變化慢的原理，使被凍存的細胞實現(xiàn)緩慢降溫。 如水、甲 醇、 異丙醇 、 乙醇的比熱容較高，分別是 、 、 、 J/(kg因此選擇特種塑料盒子作為程序冷凍盒的盒子。 已知大多數(shù) 細胞 在凍存的過程中， 降溫的速度在 1～ 2℃ /min時，細胞的損傷 最小，因此對于大多數(shù)細胞，選擇酒精和異丙醇的混合液作為程序降溫液保存細胞效果最好。s 21 win. Michel Platini, president of European football39。s 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 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 selfrighteous spiritual. 一個人的時候，自己的想法總是特別地清晰。ll 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 jump When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds