天天操夜夜拍丨国产精品超清白人精品av丨天天爽天天噜在线播放丨国产精品久久久久久久福利竹菊丨色综合天天天天做夜夜夜夜做丨国内自拍xxxx18丨白人と日本人の交わりビデオ丨午夜激情在线观看丨成人18视频丨久久66热人妻偷产精品丨视频一区二区三区在线观看丨操操操插插插丨久久的久久爽亚洲精品aⅴ丨91精品一区二区三区在线观看丨aaa女人18毛片水真多丨99re在线视频精品丨超碰免费在丨中文字幕人妻无码专区app丨午夜香蕉视频丨又大又粗欧美黑人aaaaa片丨久久夫妻视频丨乌克兰性欧美精品高清丨亚洲欧美福利视频丨少妇高潮久久久久久一代女皇丨97国产高清

1. Harvest cells from a culture that is at or near peak density. To detach cells from the wall of the culture tubes place on ice for 10 minutes.  Invert tubes several times until the majority of the cells are in suspension.  Centrifuge tubes at 800 x g for 5 minutes. 
2. Adjust the concentration of cells to 2 x 10⁷/mL in fresh medium.
3. Before centrifuging prepare a 24% (v/v) solution of sterile DMSO in fresh medium containing 8% (w/v) sucrose.  The solution is prepared as follows:
1. Add 1.05 g sucrose to 10 mL of fresh medium and filter sterilize through a 0.2 µm filter;
2. Add 2.4 mL of DMSO to an ice cold 20 x 150 mm screw-capped test tube;
3. Place the tube on ice and allow the DMSO to solidify (~5 min) and then add 7.6 mL of ice cold medium prepared in step 3a. The final concentration will be 24% (v/v) DMSO and 8% (w/v) sucrose;
4. Invert several times to dissolve the DMSO;
5. Allow to warm to room temperature.
4. Mix the cell preparation and the cryoprotective agent, prepared in step 3, in equal portions. Thus, the final concentration will equal 12% (v/v) DMSO + 4% sucrose (w/v) and 10⁷ cells/mL. The time from the mixing of the cell preparation and DMSO stock solution before the freezing process is begun should be no less than 15 min and no longer than 30 min.
5. Dispense in 0.5 mL aliquots into 1.0 - 2.0 mL sterile plastic screw-capped cryules (special plastic vials for cryopreservation).
6. Place the vials in a controlled rate freezing unit.  From room temperature cool at -1°C/min to -40°C.  If the freezing unit can compensate for the heat of fusion, maintain rate at -1°C/min through the heat of fusion.  At -40°C plunge into liquid nitrogen. Alternatively, place the vials in a Nalgene 1°C freezing apparatus.  Place the apparatus at -80°C for 1.5 to 2 hours and then plunge ampules into liquid nitrogen.  (The cooling rate in this apparatus is approximately -1°C/min.)  
7. The frozen preparations should be stored in either the vapor or liquid phase of a nitrogen refrigerator. Frozen preparations stored below -130°C are stabile indefinitely. Those stored at temperatures above -130°C are progressively less stabile as the storage temperature is elevated.
8. To establish a culture from the frozen state place an ampule in a water bath set at 35°C. Immerse the vial just to a level just above the surface of the frozen material. Do not agitate the vial.
9. Immediately after thawing, do not leave in the water bath, aseptically remove the contents of the ampule and inoculate a 16 x 125 mm screw-capped test tube containing 13 mL ATCC Medium 2695.
10. Incubate the culture on a 15° horizontal slant at 35°C.

Nash TE, et al. Restriction-endonuclease analysis of DNA from 15 Giardia isolates obtained from humans and animals. J. Infect. Dis. 152: 64-73, 1985. PubMed: 2409186

Nash TE, Keister DB. Differences in excretory-secretory products and surface antigens among 19 isolates of Giardia. J. Infect. Dis. 152: 1166-1171, 1985. PubMed: 4067331

Clark CG, Diamond LS. Methods for cultivation of luminal parasitic protists of clinical importance. Clin. Microbiol. Rev. 15: 329-341, 2002. PubMed: 12097242

Miller RL, et al. Identification of Giardia lamblia Isolates Susceptible and Resistant to Infection by the Double-Stranded RNA Virus. Exp. Parasitol. 66: 118-123, 1988. PubMed: 3366209