-
Notifications
You must be signed in to change notification settings - Fork 15
Extraction protokoll #64
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
base: master
Are you sure you want to change the base?
Changes from all commits
ed532c2
37ea457
8623daa
72a3d2a
a1c4e4d
c822c93
c8a27ea
dff8eda
88f976d
File filter
Filter by extension
Conversations
Jump to
Diff view
Diff view
There are no files selected for viewing
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,147 @@ | ||
--- | ||
layout: default | ||
title: new Beer DNA extraction | ||
image: /images/protocols/beer-dna-extraction.jpg | ||
--- | ||
|
||
## Requirements | ||
|
||
The most important: **2 bottles of beer (33cl)**. In our first prototype, we used a Chimay red. Using a non-filtered beer should give more DNA for sequencing. | ||
|
||
Needed consumables: | ||
1. Yeast DNA Extraction Kit Thermo Fischer | ||
2. TrisHCl-buffer (1M, pH 7.4) | ||
-1.0mL per sample + 50ml per sample (washing) | ||
3. 70% EtOH (for molecular biology) | ||
- 1.5mL per sample | ||
4. Isopropanol (for molecular biology) | ||
- 600µL per sample | ||
5. Sterile water (for molecular biology) | ||
- 50µL per sample | ||
6. Sterile eppis (1.5mL) | ||
- 2 per sample | ||
7. (Falcon) tubes (according to beer volume) | ||
|
||
|
||
### Before starting | ||
- Prewarm DNA Releasing Reagent A and B at 37°C for 5 min | ||
- Pre-cooled the centrifuge and tubes so that it starts at 4°C, because we hypothesize that keeping the beer at the preferred drinking temperature improves the sequencing results [proof is needed]. | ||
- Switch on thermo block at 65°C | ||
|
||
### STEP 1: Harvest the yeast from the beer | ||
1. Shake the beer bottle (a bit) | ||
2. Transfer into a 1000 ml Erlenmeyer flask (the big glass that looks like a triangle) | ||
3. You should carefully shake the Erlenmeyer to remove most of the CO2. A foam will form, whose size depends on the beer, its temperature and for how long it has been open. | ||
|
||
{: width="35%"} | ||
|
||
4. Transfer the beer (not the foam) into 50 ml tubes | ||
{: width="75%"} | ||
|
||
- Make sure each tube gets the same quantity (to balance the centrifuge for the next step) | ||
- Put a lid on each tube but don't close them until the next step (CO2 needs to be evacuated) | ||
|
||
5. Centrifuge at 4000 rpm and 4°C for 10 min | ||
Be careful that the centrifuge is correctly balanced: for each tube put one on the opposite side. | ||
|
||
This step separates the liquid phase and the solid phase (which contains yeast among other things): | ||
|
||
{: width="25%"} | ||
|
||
6. Discard carefully the supernatant either by pouring the liquid phase. But anyway, be sure that the pellet remains in the tube. | ||
7. Transfer 1 ml of TrisHCl-buffer (1M, pH 7.4) to the tube. | ||
- the buffer helps to separate the yeast cells form the rest of the beer (washing). | ||
|
||
{: width="25%"} | ||
|
||
8. Mix by pipetting to resolve the pellet (Aspirate and pull out the liquid a couple of time with the pipette. You will see that the pellet will go into solution and disappear.) Afterwards, no solid phase should be visible and the solution should turn into a brownish color. | ||
|
||
{: width="85%"} | ||
|
||
9. Fill up to 20ml whith the TrisHCl-buffer | ||
10. Centrifuge 4000 rpm 10 min 4°C | ||
11. Discard supernatant | ||
12. Resuspend the cells (with ca. 1ml 1M TrisHCl buffer pH 7.4) | ||
13. Transfer the solution into a 1.5 ml Eppendorf tube (eppi). | ||
{: width="20%"} | ||
14. Centrifuge 8000 rcf 5 min 4°C | ||
15. Discard supernatant | ||
16. Weigh each of your eppy pellets (use empty 1.5ml eppi as tara): weights of one pellet between 30mg and 60mg | ||
17. Now we like to come to approx. 70-90mg pellet per eppi: | ||
- Resolve the pellets by adding 500 μL and pipet up and down | ||
- Eventually combine or split the solution of eppis to achieve ca. 70-90 mg pellet per eppi | ||
- Centrifuge 8000 rcf 5 min 4°C | ||
- Discard supernatant | ||
|
||
|
||
|
||
### STEP 2: Break-down the yeast cell wall – first round | ||
Now, we want to get the DNA out the yeast. The DNA is well protected by the cell wall and the membrane of the nucleus. We need to break the membrane of the yeast and then the menbrane of the nucleus. | ||
|
||
{: width="50%"} | ||
|
||
*A yeast cell - Frankie Robertson, CC ASA, [Wikimedia](https://en.wikipedia.org/wiki/File:Yeast_cell_english.svg)* | ||
|
||
- Suspend cells: | ||
|
||
1. Add 640µl of the Y-PER Reagent. | ||
|
||
[Y-PER](https://www.thermofisher.com/order/catalog/product/78991#/78991) is a detergent optimized for yeast cell lysis. | ||
|
||
The amount of Y-PER reagent is calculated by taking the ratio of 8μL(reagent)/1mg pellet | ||
|
||
For simplification we assume all pellets correspond to 80 mg and added 640µl Y-PER | ||
|
||
2. Mix by pipetting up and down until the mixture is homogenous | ||
|
||
- Incubate at 65°C for 10 - 30 minutes. | ||
- Centrifuge at 13,000 rcf for 5 minutes | ||
- Discard supernatant | ||
|
||
|
||
### STEP 3: Break-down the yeast cell wall – second round | ||
|
||
- Add 400μL of DNA Releasing Reagent A | ||
- Add 400μL of DNA Releasing Reagent B | ||
|
||
A protein Removal Reagent can be protease to digest proteins or a salt solution to precipitate protein (salting-out). | ||
|
||
- Mix by pipetting up and down until the mixture is homogenous | ||
- Incubate at 65°C for 10 - 30 minutes. | ||
|
||
|
||
### STEP 4: Stop protein activity in the solution | ||
- Add 200μL of Protein Removal Reagent to mixture | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. Protein Removal Reagent is probably either protease to digest proteins or a salt solution to precipitate protein (salting-out). |
||
- Invert eppy several times (>20x) | ||
- Centrifuge at least 13,000 rcf for 5 minutes | ||
- Transfer supernatant (only 900µl!!!!!) to a new 1.5mL eppy | ||
- try to not touch the pellet with the pipet tip | ||
|
||
|
||
### STEP 5: Separate the DNA from other molecules | ||
There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. DNA is negatively charged, therefore hydrophilic (dissolves in water). The carbon chain of alcohol is hydrophobic, so the DNA is less soluble and precipitates. Isopropanol has a longer carbon chain than ethanol (is more hydrophobic) and thus precipitates DNA stronger than ethanol. There was a problem hiding this comment. Choose a reason for hiding this commentThe reason will be displayed to describe this comment to others. Learn more. We could add here a figure of Isopropanol and ethanol? |
||
- Add 600μL isopropyl alcohol to fill tube | ||
- Invert eppy several times gently (>20x) | ||
- Separate DNA by centrifuging the mixture at 13,000 rcf for 10 minutes. | ||
- The DNA should be at the bottom of the eppy (pellet) | ||
- Remove supernatant (here: liquit above you), being careful not to discard any of the pellet, which is clear and hard to see. | ||
|
||
DNA is negatively charged, therefore hydrophilic (dissolves in water). The carbon chain of alcohol is hydrophobic, so the DNA is less soluble and precipitates. Isopropanol and ethanol are alcohol. Isopropanol has a longer carbon chain than ethanol (therefore more hydrophobic) and thus precipitates DNA stronger than ethanol. | ||
The problem is that isopropanol also precipitates salts. To remove salts, we wash the DNA pellet with ethanol in STEP 6. | ||
|
||
|
||
### STEP 6: Wash the DNA to remove unwanted substances | ||
- Add 1.5mL of 70% ethanol to the pellet | ||
- invert eppy several times (>20x) | ||
- Centrifuge at 13,000 rcf for 1 minute to wash off any residual salts or cellular debris clinging to the DNA or tube. | ||
- Invert the eppy carfully but in one go to remove the liquide, without damageing the pellet | ||
- to dry any residual ethanol before proceeding to Step 7 place the eppy up side down on a tissue. (took approx. 30-45min) | ||
|
||
### STEP 7: Resuspend the DNA | ||
|
||
- add 50μL sterile water to each eppy | ||
- Flick the bottom of the tube carefully, or pipette solution up and down | ||
- Wash the sides of the tubes until all the genomic DNA is in solution (should take 5 min) | ||
- Freeze the DNA until library preparation or start directly! | ||
|
||
Well done! Now you have successfully extracted beer DNA! [Go on and sequence your extracted DNA]({% link _protocols/beer-dna-sequencing.md %}) or visit the next pub... | ||
|
Uh oh!
There was an error while loading. Please reload this page.