Plasmid DNA Purification
MACHEREY-NAGEL – 01/2008/ Rev. 04
14
4.5
Culture volume for low-copy plasmids
NucleoBond
®
Xtra
kits are designed for isolation of high-copy plasmids (up to sev-
eral hundred copies/cell) as well as low-copy plasmids (<20 copies/cell). However,
when purifying low-copy plasmids, the cell mass and the lysis buffer volumes should
be increased at least by factor 2 to provide enough DNA to utilize the columns´ bind-
ing capacity. Table 3 shows recommended ODVs and the corresponding pairs of
OD
600
and culture volume for low-copy plasmid cell cultures (for detailed information
on calculating ODV = OD
600
x Vol. refer to section 4.4).
For higher yields, it is advantageous to increase the cell culture and lysis buffer vol-
umes even more, e.g. by factor 3-5. In this case additional lysis buffer can be ordered
separately (see section 8.2 for ordering information). Furthermore, a centrifuge
should be used for lysate clarification instead of the provided
NucleoBond
®
Xtra
column filters
since their capacity for precipitate is limited.
Table 3: Suggested culture volumes for low-copy plasmids
Recommended culture volume for
NucleoBond
®
Xtra kit
Pellet
wet
weight
Rec.
ODV
OD
600
=
2
OD
600
=
4
OD
600
=
6
OD
600
=
8
OD
600
=
10
Midi
1.50 g
800
400 ml
200 ml
133 ml
100 ml
80 ml
Maxi
4.50 g
2400
1200 ml
600 ml
400 ml
300 ml
240 ml
