Lister 427 VSG 221 (TetR T7RNAP) transgenic bloodstream form
Biosafety Level
2
Biosafety classification is based on U.S. Public Health Service Guidelines, it is the responsibility of the customer to ensure that their facilities comply with biosafety regulations for their own country.
Isolation
Unknown; possibly derived from s427 strain, Uganda, 1960
Product Format
frozen
Storage Conditions
Frozen Cultures: -70°C for 1 week; liquid N2 vapor for long term storage
Freeze-dried Cultures: 2-8°C
Live Cultures: See Protocols section for handling information
Harvest cells from a culture which is at or near peak density by centrifugation at ~800 x g for 5 min.
Adjust concentration of cells to 0.5–1.0 x 107/mL in fresh growth medium. If the concentration is too low, centrifuge at ~800 x g for 5 minutes and resuspend the cell pellet with a volume of supernatant to yield the desired concentration.
While cells are centrifuging, prepare a 20% (v/v) solution of sterile glycerol in fresh growth medium.
Mix the cell preparation and the glycerol solution in equal portions. The final concentration will be 2.5-5 x 106 cells/mL in 10% glycerol. The time from the mixing of the cell preparation and glycerol stock solution before the freezing process is begun should be no less than 15 min and no more than 30 min.
Dispense in 0.5 mL aliquots into 1.0 - 2.0 mL sterile plastic screw-capped cryovials.
Place the ampules 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.) If freezing unit can compensate for the heat of fusion, maintain rate at -1°C/min through heat of fusion. At -40°C, plunge ampules into liquid nitrogen.
Store in either the vapor or liquid phase of a nitrogen refrigerator.
To thaw a frozen ampule, place it in a 35°C water bath such that the lip of the ampule remains above the water line. Thawing time is approximately 2 to 3 minutes. Do not agitate the ampule. Do not leave ampule in water bath after it is thawed.
Remove the vial from the water bath immediately after thawing. Aseptically transfer the contents of the ampule into 10 mL of fresh growth medium.
Incubate at 37°C under 5% CO2 atmosphere.
Maintain as described above.
Name of Depositor
G Cross
References
Wirtz E, et al. A tightly regulated inducible expression system for conditional gene knock-outs and dominant-negative genetics in Trypanosoma brucei. Mol. Biochem. Parasitol. 99(1): 89-101, 1999. PubMed: 10215027
Cunningham MP, Vickerman K. Antigenic analysis in the Trypanosoma brucei group, using the agglutination reaction. Trans. R. Soc. Trop. Med. Hyg. 56: 48-59, 1962. PubMed: 13882652
Cross GA, Manning JC. Cultivation of Trypanosoma brucei sspp. in semi-defined and defined media. Parasitology 67(3): 315-331, 1973. PubMed: 4761771
Peacock L, et al. Fly transmission and mating of Trypanosoma brucei brucei strain 427. Mol Biochem Parasitol 160(2): 100-106, 2008. PubMed: 18524395
