Using a sterile toothpick, pick/scratch a single colony from the transformants. Drop the toothpick into a plastic tube with 3 mL sterile liquid medium with the appropriate antibiotic(s). Close the tube but leave the cap slightly open to allow oxygen to enter, and incuate at 37 C with shaking.
DNA Isolation
We use the Promega Wizard Plus SV Minipreps DNA Purification System A1460 with the sentrifugation version of the protocol supplied by the vendor.
Agarose with Gel Green is used when molding the gel. Choose an appropriate ladder as a referance to size of the fragments and put 2 µl of ladder in wells on either side of the samples. When applying the samples, add 20% loading dye to the sample. For instance, if the initial sample is 10 µl, add 2 µl loading dye. Apply the samples to individual wells in the gel.
Let the gel run for 45 min at 90 V, and if the bands are poorly separated, run a little longer. Beware that if the gel runs for a very long time, the smaller bands may move out of the gel.
Gel purification
We are using the QIAquick Gel Extraction kit, following the protocol from www.qiagen.com.
[3]
Preparation of samples for RNA isolation
Grow overnight cultures
Mix 1 ml cell culture with 2 ml RNA-protect (QIAGEN)
Vortex for 5 seconds
Incubate for 5 minutes in room temperature
Spin down at 6000 g for 10 minutes in 4 °C
RNA isolation
(RNAquenous kit from Ambion)
Add 100 µl Lysozyme/TE-mix to each sample
Incubate for 5 minutes in room temperature
Add 300 µl lysis/binding solution
Vortex to make sure everything is solved
Add 400 µl water for 64 % ethanol
Turn the tubes 4 times, and transfer to filtertubes
Centrifuge for 1 minute at 13000 g
Add 700 µl wash solution 1
Centrifuge for 1 minute at 13000 g
Add 500 µl wash solution 2/3
Centrifuge for 1 minute at 13000 g
Add 500 µl wash solution 2/3
Centrifuge for 1 minute at 13000 g
Centrifuge for an additional minute at 13000 g
Add 40 µl preheated elution buffer
Centrifuge for 1 minute at 13000 g
Add 20 µl preheated elution buffer
Centrifuge for 1 minute at 13000 g
Measure concentrations on NanoDrop
DNAse reaction
Calculate the volume of RNA solution necessary to obtain a total of 3000 ng RNA
Add SIV to 25 µl
Add 2.7 µl DNAse buffer and 1 µl DNAseI
Incubate for 30 minutes at 37 °C
Add 5 µl inactivation mixture and flip the tubes
Incubate for 2 minutes in room temperature
Centrifuge for 2 minutes at 13000 g
Transfer 2 µl of the supernatant to a new tube and add 18 µl SIV
Incubate for 10 minutes at 65 °C
cDNA reaction
Prepare bulk mixture:
5 µl bulk reaction mixture
1 µl RNA primers
1 µl DTT
Mix 4 µl sample with 3.5 µl bulk mixture
Incubate for 1 hour at 37 °C
If qPCR is not to be performed immediately, the cDNA samples should be frozen down at -80 °C
Mastermix for real time PCR
Coming soon...
OD measurements
Unless otherwise noted, all OD measurements are made at 600 nm with a PerkinElmer Lambda 35 spectrometer, with un-inoculated medium as reference.
Fluorescence measurements
Fluorescence were measured with a Tecan Infinite M200 Pro microplate reader using Nunclon flat bottom black polystyrol 96 well plates.
Recipes
Growth media
LB-medium (LB-Lennox):
Antibiotics
Ampicillin stock solutions: 100 mg/mL dissolved in MQ water
Kanamycin stock solutions: 100 mg/mL dissolved in MQ water
Chloramphenicol: 34 mg/mL dissolved in 100% ethanol
Store at -20 C after preparation and between use.
Ampicillin media concentration: 100 ug/mL = 1 mL stock solution/L medium
Kanamycin media concentration: 100 ug/mL = 1 mL stock solution/L medium
Chloramphenicol media concentration: 24 ug/mL = 0.7 mL stock solution/L medium
When transforming low copy number plasmids, it may be necessary to reduce the antibiotic to allow for the reduced antibiotic resistance of the tranformant.
Glycerol stocks
Prepare a solution of 60 % glycerol in water. Add 400 uL glycerol solution and 800 uL of the culture to be stored in a cryogenic tube. Place in 5 C refrigerator for 30 min, then move to -80 C freezer.
Cake
Batter is prepared following the protocol by Kakemonsen (1). Sliced pieces of Malus domestica is inserted into the batter, while sucrose and ground Cinnamomum verum bark is mixed 2:1 by volume and distributed evenly on top of the batter, which is placed in a 26 cm diameter open-top vessel. The mixture is incubated in a dry air oven at ~180 C for 45 min.
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