Process for preparing plasmid in large scale with high yield
A large-scale, high-yield technology, applied in the fields of DNA preparation, sugar derivatives, organic chemistry, etc., can solve the problems of poor quality and purity, not suitable for gene therapy and gene immunity, etc., and achieve the effect of increasing yield
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Publication Date
- 2002-10-09
- Estimated Expiration
- Not applicable · inactive patent
Abstract
Description
Technical field:
[0001] The invention provides a high-yield large-scale plasmid preparation method, relates to the improvement of the alkali denaturation-PEG precipitation method, and belongs to the technical fields of molecular biology, gene therapy and gene immunity. Background technique:
[0002] The classic methods for large-scale preparation of plasmids are alkali denaturation-CsCl density gradient ultracentrifugation and alkali denaturation-PEG precipitation. Alkaline denaturation-CsCl density gradient ultracentrifugation can produce high-quality plasmids, but it requires high equipment conditions, high cost, and low yield, so it is rarely used. The yield of the plasmid prepared by the alkali denaturation-PEG precipitation method is relatively large, and the yield per 1000ml of bacteria is about 4-10mg, which is much higher than the yield of the plasmid prepared by the alkali denaturation-CsCl density gradient ultracentrifugation method and column chromatography kit. ...
Examples
Embodiment 1
[0014] 1. Cultivation and collection of recombinant bacteria: Pick a single colony of interest and inoculate 55ml of LB medium (add corresponding amount of resistant drugs, the same below) to OD 600 ≈0.6, → Take 50ml (another 5ml for identification) and pour it into 1000ml LB medium for about 12-16 hours; → Centrifuge at 5000rpm for 10 minutes, discard the supernatant, and collect the bacteria.
[0015] 2. Preparation of protoplasts: Add 50ml of 20% sucrose and 50mM Tris-HCl (pH 8.0) to the bacterial pellet and suspend by blowing; → ice bath for 3-5 minutes; → add 10ml with pre-cooled 0.25M Tris-HCl (pH 8.0 ) prepared fresh lysozyme solution (5mg / ml), ice bath for 5 minutes; → add 20ml pre-cooled 0.25M EDTA (pH 8.0), ice bath for 5 minutes; → add 20ml pre-cooled 0.25M Tris-HCl (pH 8.0), 37°C water bath for 5 minutes; → Immediately, 4°C, 6000rpm, 10 minutes, discard the supernatant. (Ice bath conditions and exposure time are critical)
[0016] 3. Extraction and purification o...
Embodiment 2
[0022] Purify pcDNA3 plasmid from BL21(DE3) transformed recombinant bacteria, 2000LB medium, 46mg plasmid.
[0023] 1. Colony culture and collection: Pick a single colony transformed with pcDNA3 and inoculate 110ml LB medium (add ampicillin to 60μg / ml) to OD 600 ≈0.6, → take 100ml and pour it into 2000ml LB medium and cultivate for about 12-16 hours;
[0024] → Centrifuge at 5000rpm for 10 minutes, discard the supernatant, and collect the bacteria.
[0025] 2. Protoplast preparation: add 100ml of 20% sucrose and 50mM Tris-HCl (pH 8.0) to the bacterial pellet, and pipette to suspend;
[0026] → Ice bath for 5 minutes;
[0027] → Add 20ml of fresh lysozyme solution (5mg / ml) prepared with pre-cooled 0.25M Tris-HCl (pH 8.0), and ice bath for 5 minutes;
[0028] → Add 40ml of pre-cooled 0.25M EDTA (pH 8.0), ice bath for 5 minutes;
[0029] → Add 40ml of pre-cooled 0.25M Tris-HCl (pH 8.0), bathe in water at 37°C for 5 minutes;
[0030] → Immediately at 4°C, 6000rpm, 10 minutes,...
Embodiment 3
[0050] Purify pVAX1 plasmid from JM109 transformed recombinant bacteria, 1000LB medium, 21mg plasmid
[0051] 1. Colony culture and collection: Pick a single colony of JM109 transformed by pVAX1 and inoculate 55ml LB medium (kanamycin to 30μg / ml) to OD 600 ≈0.6, → take 50ml (the other 5ml is used for identification) and pour it into 1000ml LB medium for about 14 hours;
[0052] → Centrifuge at 5000rpm for 10 minutes, discard the supernatant, and collect the bacteria. 2. Protoplast preparation: Add 50ml of 20% sucrose and 50mM Tris-HCl (pH 8.0) to the bacterial pellet, and pipette to suspend;
[0053] → Ice bath for 5 minutes;
[0054] → Add 10ml of fresh lysozyme solution (5mg / ml) prepared with pre-cooled 0.25M Tris-HCl (pH 8.0), and ice bath for 5 minutes;
[0055] → Add 20ml of pre-cooled 0.25M EDTA (pH 8.0), ice bath for 5 minutes;
[0056] → Add 20ml of pre-cooled 0.25M Tris-HCl (pH 8.0), bathe in water at 37°C for 5 minutes;
[0057] → Immediately at 4°C, 6000rpm, 10...