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Team:Freiburg/Content/Notebook/Labjournal
From 2014.igem.org
Cloning
Cloning - May
Cloning - June
Cloning - July
Cloning - August
Cloning - September
Cloning - October
Viral Vectors
Viral Vectors - May
2014/05/21
Transfection/ Virus production
For virus production Phoenix cells (producer cell line) were splitted (well separated) on 100mm plates. At 70% cell density cells were transfected using polyethylenimine.
- remove medium and refill with 5 ml new completed growth medium (DMEM)
- 600 µl transfection mastermix was prepared (8 µg pMIG IRES EGFP, 24 µl PEI, rest OptiMEM)
- mastermix was incubated 15 min and carefully drop on the plates
Plates were incubated at 37°C. The supernatant after 24 was removed and refilled with 5 ml new DMEM, the supernatant was collected after 48 h (refilled with 5 ml DMEM) as well as 72 h.
Phoenix cells transfected with pMIG IRES EGFP one day after transfection.
2014/05/25
Transduction mouse cells
NIH 3T3 cells (60% density) were transduced with MuLV IRES EGFP.
- 500 µl of supernatant was removed
- 1 µl Polybrene was added (10mg/ml)
- 500 µl virus supernatant was added (sterile filtered)
- incubation at 37°C for 6h
- cell supernatant was replaced with fresh DMEM
- transduction was repeated once
Pictures could be made after 48 h of incubation.
NIH 3T3 cells were transduced twice with MuLV IRES EGFP for 6h. Picture was made after 48 h of incubation at 37°C.
Viral Vectors - June
2014/06/20
Thawing of eukaryotic cells
New Phoenix cell stocks were thawed:
- cryotube was thawed at 37°C water bath until almost defrosted
- stock was filled in 9 ml warm completed growth medium and centrifuged at 900 rpm for 2 min
- medium was removed and refilled with 10 ml warm completed growth medium
- cells were seeded on 100 mm plates
Testing optimal cell density of mouse fibroblasts
NIH 3T3 have a really fast growth so that we tested the optimal cell number for seeding NIH 3T3 for having around 60% cell density on the next day. NIH 3T3 cells grow very fast; therefore we have tested the optimal seeding cell number to obtain 60% cell density on the next day. Results indicate that the optimal cell number is 1 &ndash 1.5x10^5 cells per well ( = 0.5 – 0.75 cells/ml)
2014/06/22
Transfection/ Virus production
Transfection of Phoenix cells (70% density) with pMIG IRES EGFP (protocol: 2014/05/21) (2 x 100mm plate)
3 Phoenix cells transfected with pMIG IRES EGFP.
2014/06/24
Transfection/ Virus production
Transfection of Phoenix cells (70% density) with pMIG IRES EGFP (protocol: 2014/05/21) (5 x 100mm plate)
2014/06/27
Thawing new HEK 293 cells
(protocol: 2014/06/20)
Transfection CHO cells with receptor
Transfection of CHO cells with SLC7a1 (for later transduction with virus). Medium was changed after 5 h. Cells were incubated for 24 h before viral transduction with MuLV IRES EGFP, medium change after 16 h.
(left) Cho cells without receptor were transduced with MuLV IRES EGFP ,(right) CHO cells transfected with SLC7a1 and transduced with MuLV IRES EGFP (24h after transfection). Analyses with flow cytometry indicates that 5% of cells were transfected (transfection control) and 2% of cells transfected with the receptor were infected with MuLV.
2014/06/27
Transduction mouse cells (different incubation times)
NIH 3T3 cells (60% density) were transduced with MuLV IRES EGFP and incubated for 8, 16, 24 and 2 x 8 hours. Virus was taken from different supernatants (an older one and a newer one) to see, if it makes any difference. Cells were infected with supernatant (500µl viral supernatant, 500µl completed growth medium + 1µl Polybrene/ml) harvested at different time points. Results indicate that there was no difference between older and newer virus; best results were given with an infection time of 2 x 8 hours.
For testing, if centrifugation brings better transduction efficiencies, mouse cells were infected with the different viral supernatants and centrifuged for 45 min, 1800 rpm, 32°C. In two wells it was tested if the double amount of Polybrene brings better transduction efficiencies. However, we found out that cells were death after centrifugation.
