Plasmid+ vs LB media

PLASMID+ liquid medium is an enriched medium specifically designed for plasmid DNA production. PLASMID+ supports much higher cell densities and plasmid yields than LB media. Optimal shake flask yields are achieved using Ultra Yield™ Flasks (Thomson Instrument Company), which facilitate maximum culture aeration. PLASMID+ medium may also be used in a bioreactor with continuous aeration and agitation.
Bacteria Strains

E. coli DH5α is the preferred host strain for use with PLASMID+ medium. E. coli XL1-Blue also produces high quality plasmid DNA and may improve plasmid DNA yields with plasmids smaller than 3kb.
Seed Culture

A seed culture is recommended for culture volumes larger than 50mL. Cultures less than 50mL may be inoculated directly from a glycerol stock or plate. To prepare a seed culture, use a glycerol stock or plate to inoculate 1/100th of the final culture volume of LB + appropriate antibiotic (e.g. 100 μg/mL ampicillin; 50 μg/mL kanamycin) and grow to saturation with shaking at 37°C.
Ultra Yield Flask Cultures

Using aseptic technique, add PLASMID+ medium and appropriate antibiotic (e.g. 100μg/mL ampicillin; 50μg/mL kanamycin) to one or more Ultra Yield™ Flasks; see Table 1 for recommended culture volumes. Inoculate the medium, place an AirOtop seal on the flask, and grow at 37°C with shaking at 350 rpm for 16-18 hours.
Plasmid DNA Purification from PLASMID+ Cultures

Plasmid DNA may be purified from PLASMID+ cultures by the common methods (e.g. Qiagen* Mega/Giga kits, etc.). Mega kits we have found starting with 5mgs works well at the high range. Giga kits we have found starting with 20mgs works well at the high range. However, because PLASMID+™ medium typically yields 5-10 times increased yields when compared to LB media, the increased cell mass and plasmid DNA content must be taken into consideration to insure efficient lysis and to avoid overloading purification columns. When using plasmid purification kits, the culture volume per purification should be decreased by a factor of 5 with respect to the recommended LB culture volume.

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Science & Technology

Tags:

• Plasmid vs LB media
• DNA growth
• lb broth
• lb
• plasmids
• DNA production
• plasmid yield
• LB media
• Ultra Yield flasks
• Airotop enhanced seals
• bioreactor
• Bacteria Strains
• E. coli
• plasmid DNA