Team:TU Delft/protocols/midi-prep plasmid isolation
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(New page: ==Qiagen Midi-prep plasmid isolation== This protocol is based on QIAGEN® Plasmid Purification Handbook. This protocol is designed for preparation of up to 100 µg of high- or low-copy p...) |
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- | + | =Qiagen Midi-prep plasmid isolation= | |
- | + | ||
This protocol is based on QIAGEN® Plasmid Purification Handbook. | This protocol is based on QIAGEN® Plasmid Purification Handbook. | ||
- | This protocol is designed for preparation of up to 100 µg of high- or low-copy plasmid or cosmid DNA using the Qiagen Plasmid Midi Kit. | + | This protocol is designed for preparation of up to 100 µg of high- or low-copy plasmid or cosmid DNA using the Qiagen Plasmid Midi Kit. Qiagen plasmid isolation is used to obtain very pure plasmid DNA. |
- | Qiagen plasmid isolation is used to obtain very pure plasmid DNA. | + | |
- | + | ||
Maximum recommended culture volumes for the Qiagen-tip 100: | Maximum recommended culture volumes for the Qiagen-tip 100: | ||
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- | + | ''Materials:'' | |
+ | |||
+ | - bacterial culture | ||
+ | |||
+ | - Qiagen colums | ||
+ | |||
+ | - buffer P1 (100 mg/mL RNAse A, 50 mM Tris/HCl, 10 mM EDTA, pH 8.0) | ||
+ | |||
+ | - buffer P2 (200 mM NaOH, 1% SDS) | ||
+ | |||
+ | - buffer P3 (3 M KAc, pH 5.5) | ||
+ | |||
+ | - buffer QBT (750 mM NaCl, 50 mM MOPS, 15% Ethanol, pH 7.0, 0.15% Triton X-100) | ||
- | + | - buffer QC (1 M NaCl, 50 mM MOPS, 15% Ethanol, pH 7.0) | |
- | + | - buffer QF (1.25 M NaCl, 50 mM Tris/HCl, 15% Ethanol, pH 8.5) | |
- | + | - isopropanol | |
- | + | - milliQ | |
- | + | - centrifuge | |
- | + | - nanodrop | |
- | |||
- | + | ''Protocol:'' | |
- | + | 1. Pick a single colony from a freshly streaked selective plate and inoculate a starter culture of 25 to 100 mL LB medium containing the appropriate selective antibiotic. Incubate for approximately 8 h at 37°C with vigorous shaking (approx. 300 rpm) | |
- | + | 2. Harvest the 25 to 100 mL bacterial cells by centrifugation at 4.000 rpm for 15 min at 4°C ( Sorvall buckets). If you wish to stop the protocol and continue later, freeze the cell pellets at –20°C | |
- | + | 3. Resuspend the bacterial pellet in 4 mL of chilled Buffer P1 (containing RNAse) and pour into a blue cap 50 mL tube | |
- | + | 4. Add 4 mL of Buffer P2, mix gently but thoroughly by inverting 4–6 times, and incubate at room temperature for 5 minutes | |
- | + | 5. Add 4 mL of chilled Buffer P3, mix gently by inverting 4–6 times, and incubate on ice for 15 minutes | |
- | + | 6. Centrifuge 30 min at 4.000 rpm and pour supernatant through cheesecloth into a fresh blue cap 50 mL tube | |
- | + | 7. During centrifugation equilibrate a Qiagen-tip 100 by applying 4 mL Buffer QBT, and allow the column to empty by gravity flow | |
- | + | ||
- | + | 8. Apply the supernatant from step 6 onto the Qiagen-tip and allow it to enter the resin by gravity flow | |
+ | 9. Wash the Qiagen-tip with 2 × 10 mL Buffer QC | ||
- | + | 10. Elute DNA with 5 mL Buffer QF into 15 mL blue cap tube | |
- | + | 11. Precipitate DNA by adding 3.5 mL (0.7 volumes) room-temperature isopropanol to the eluted DNA | |
- | + | 12. Mix and centrifuge immediately at 4.000 rpm for 30 minutes at 4 °C | |
- | + | 13. Proceed immediately when centrifuge stops and carefully decant the supernatant | |
- | + | 14. Wash DNA pellet with 2 mL of cold 70% ethanol, and centrifuge at 4.000 rpm for 10 minutes at 4 °C | |
- | + | 15. Carefully decant the supernatant without disturbing the pellet | |
- | + | 16. Air-dry the pellet for 5–10 min (has to be dry), and redissolve the DNA in a suitable volume of milliQ H2O | |
- | + | 17. Measure DNA concentration on the Nanodrop. |
Latest revision as of 11:05, 12 September 2010
Qiagen Midi-prep plasmid isolation
This protocol is based on QIAGEN® Plasmid Purification Handbook. This protocol is designed for preparation of up to 100 µg of high- or low-copy plasmid or cosmid DNA using the Qiagen Plasmid Midi Kit. Qiagen plasmid isolation is used to obtain very pure plasmid DNA.
Maximum recommended culture volumes for the Qiagen-tip 100:
High-copy plasmids 25 mL
Low-copy plasmids 100 mL
Materials:
- bacterial culture
- Qiagen colums
- buffer P1 (100 mg/mL RNAse A, 50 mM Tris/HCl, 10 mM EDTA, pH 8.0)
- buffer P2 (200 mM NaOH, 1% SDS)
- buffer P3 (3 M KAc, pH 5.5)
- buffer QBT (750 mM NaCl, 50 mM MOPS, 15% Ethanol, pH 7.0, 0.15% Triton X-100)
- buffer QC (1 M NaCl, 50 mM MOPS, 15% Ethanol, pH 7.0)
- buffer QF (1.25 M NaCl, 50 mM Tris/HCl, 15% Ethanol, pH 8.5)
- isopropanol
- milliQ
- centrifuge
- nanodrop
Protocol:
1. Pick a single colony from a freshly streaked selective plate and inoculate a starter culture of 25 to 100 mL LB medium containing the appropriate selective antibiotic. Incubate for approximately 8 h at 37°C with vigorous shaking (approx. 300 rpm)
2. Harvest the 25 to 100 mL bacterial cells by centrifugation at 4.000 rpm for 15 min at 4°C ( Sorvall buckets). If you wish to stop the protocol and continue later, freeze the cell pellets at –20°C
3. Resuspend the bacterial pellet in 4 mL of chilled Buffer P1 (containing RNAse) and pour into a blue cap 50 mL tube
4. Add 4 mL of Buffer P2, mix gently but thoroughly by inverting 4–6 times, and incubate at room temperature for 5 minutes
5. Add 4 mL of chilled Buffer P3, mix gently by inverting 4–6 times, and incubate on ice for 15 minutes
6. Centrifuge 30 min at 4.000 rpm and pour supernatant through cheesecloth into a fresh blue cap 50 mL tube
7. During centrifugation equilibrate a Qiagen-tip 100 by applying 4 mL Buffer QBT, and allow the column to empty by gravity flow
8. Apply the supernatant from step 6 onto the Qiagen-tip and allow it to enter the resin by gravity flow
9. Wash the Qiagen-tip with 2 × 10 mL Buffer QC
10. Elute DNA with 5 mL Buffer QF into 15 mL blue cap tube
11. Precipitate DNA by adding 3.5 mL (0.7 volumes) room-temperature isopropanol to the eluted DNA
12. Mix and centrifuge immediately at 4.000 rpm for 30 minutes at 4 °C
13. Proceed immediately when centrifuge stops and carefully decant the supernatant
14. Wash DNA pellet with 2 mL of cold 70% ethanol, and centrifuge at 4.000 rpm for 10 minutes at 4 °C
15. Carefully decant the supernatant without disturbing the pellet
16. Air-dry the pellet for 5–10 min (has to be dry), and redissolve the DNA in a suitable volume of milliQ H2O
17. Measure DNA concentration on the Nanodrop.