Biohazard: Should be treated as Risk Group Level 2 organisms for laboratory handling.
All handling, storage and disposal of biohazard waste must be in accordance with University rules and regulations.
Materials:
1) 48-well Tissue Culture Microplate
2) Puromycin (Sigma)
3) Hexadimethrine bromide (Sigma)
4) Target Cell Line (MCF-7 and MCF-7/Adr breast cancer cells)
5) DMEM Media
6) FBS
7) Penicillin-Streptomycin
8) 50ml Falcon Tubes
9) 15ml Falcon Tubes
10) 1.5ml RNase Free Tubes
Mission® shRNA Transduction Particles:1) Non-target control (scramble) transduction particles (Sigma #SHC002V)
Virus titer (Lot 1201010801MN): 1.1×107 TU/ml
2) STAT3 transduction particles (Sigma # NM_003150)
Virus titer: >1×106 TU/ml
Target set (5-clones)
A) TRCN0000020839
B) TRCN0000020840 (validated info => 61% in A549 cells)
C) TRCN0000020841
D) TRCN0000020842 (validated info => 76% in A549 cells)
E) TRCN0000020843 (validated info => 72% in A549 cells)
300 µl/well in 48 well plate
MOI = 1---> Non-target 842 843 Pool (842+843) Hex. Control cells
MOI = 2---> Non-target 842 843 Pool (842+843) Hex. Control cells
Notes:
Every 48-well plate experiment should include:
1. Negative control-Non-target control well (in duplicate)
2. Each clone of shRNA contruct well (in duplicate)
3. A hexadimethrine bromide control only (in duplicate) to determine cell sensitivity
4. A control well with no infection (in duplicate)
Before Starting:
1) Make DMEM media with 10% FBS and 1% PS
2) Prepare a Puromycin stock at 10 mg/ml with sterile water. Aliquot into 1.5mL e-tubes, and store at -20°C.
3) Prepare a hexadimethrine bromide stock solution (2 mg/ml)with sterile water/or media. Add to media to final concentration 8 µg/ml, and filter through syringe filer.
Procedure:
Day One:
1) Cell seeding 5×104 cells/cm2 (/well) in a 48-well plate
70% cell confluency during the day of transduction
Medium for cell seeding: DMEM containing 10% FBS, 1%PS
2) Incubate in a 37ºC incubator at 5% C02 overnight undisturbed.
Day Two:
1) Thaw lentivirus at room temperature (from -70ºC freezer).
2) While virus is thawing, warm DMEM supplemented with 10% FBS and 1%PS.
3) Aspirate the media and replace 200 µl fresh medium containing 12 µg/ml hexadimethrine bromide (final conc. 8 µg/ml in 300 µl).
4) Once the virus is fully thawed, transfer the proper amount for infection to a fresh 1.5ml e-tube containing DMEM to give 100 µl mix per well.
5) Add 100 µl of media containing virus to the cells.
6) Gently mix by swirling the plates and return back to the incubator.
7) Check cytotoxicity after 4 h by observing cells under microscope and change fresh media when toxicity occurs, if not incubate 18-48 h.
Notes:
An infectious viral titer needs to be determined prior to transduction. Add proper MOI (See Sigma protocol for calculations)
When transducing a lentiviral construct into a cell for the first time, a range of volume or MOI should be tested. 2,5,10 and 15 ul of lentiviral particles per 1.6 × 104 cells or MOIs of 0.5,1,2, and 5 should be used to determine the optimal transduction efficiency and knockdown for the each cell line.
You do not want to disturb or stress the cells. Be careful when adding the media.
Be sure to mark which wells in the plate have received which shRNA.
Day Three:
1) Remove the virus media and replace with DMEM media supplemented with 10% FBS and 1% PS.
2.) Place plate back in the incubator and incubate at 37ºC.
Day Four:
Observe the cells under microscope.
Aspirator the old media and replace fresh media with 500 ul of DMEM supplemented with10% FBS, 1%PS and the proper concentration of Puromycin (according to Kill-curve).
Day Five:
1) If cells are confluent, scale up by passaging to 6 well plate (10 cm2).
2) Continue adding puromycin 1 µg/ml.
Note: The concentration of Puromycin is going to be different with each cell line as some are more sensitive to the drug than others. It is crucial to do a kill curve with each cell line and pick the lowest concentration of Puromycin that will completely kill non-selected cells within 7-10 days.
MCF-7 cells need 0.5 µg/ml Puromycin whereas MCF-7/Adr cells require more than 5 µg/ml.
Two Weeks Later:
1) Watch the cells carefully over the next 2 weeks, passaging the cells and changing the media as necessary.
NOTE: Be sure each media change or passage contains Puromycin. Once the cells are recovering well from the Puromycin selection (depending on transduction efficiency, many cells may be killed off and it can take a while to grow the transduced cells), you may transfer them to a the culture flask/make lyophilized stocks for further propogation.
2) Confirm your stable cells for particular or known target gene/protein expression by
a) Extract RNA from cells and run RT-PCR experiments.
b) Or Extract cellular proteins and perform Western blot.
Good Luck!!!
References:
1. Dharmacon
2. Sigma
3. Internet references