BAC and Fosmid DNA
Isolation using 96 deep well, blocks, pipetting on the Hydra 96, and growth in
the HiGro Shaker for 454 sequencing
As modified by Fares Najar in the Roe
Lab at the University of Oklahoma ACGT
Updated December 15, 2009
1.
Pick a smear of colonies and inoculate 3 ml LB medium
containing the appropriate antibiotic.
2.
Grow the culture overnight at 37oC by shaking at
250 rpm in the Floor Shaker for 8-10 hours to produce a "starter
culture". For multiple
projects, this step can be accomplished using the 96-deep well block [Beckman
(cat#140504)].
3.
Add 1 ml of LB medium containing the appropriate antibiotic
to each well in a 96 deep well block [Beckman (cat#140504)].
4.
Inoculate 15 ul of the starter culture into each well using the
Eppendorf repeater pipette or the Hydra if the starter culture is in a 96-deep
well block with 8 deep wells per BAC*.
5.
Grow the BAC clone for 8-10 hours at 37oC shaking
at 500 rpm in the HiGro.
6.
Centrifuge the blocks at 3000 rpm for 10 minutes. Discard
the supernatant.
7.
Add 40 ul of 10mM EDTA to each well using the Hydra .
8.
Incubate on a table-top shaker for 10 minutes at speed of 7.
9.
Using the Hydra, add 80 ul of lysis buffer (1% SDS, and 0.2
N NaOH) to each well. Incubate at room temperature WITHOUT AGITATION OR
SHAKING until a clear lysate is
developed. It takes approximately
3 - 5 minutes for the clear lysate to develop.
10. Add 60 ul
3M potassium acetate (KOAc), pH 4.5 to each well using the Hydra.
11. Incubate on
ice for 30 minutes WITHOUT AGITATION OR SHAKING
12. Freeze the
blocks at -70oC overnight.
13. Remove the
blocks from freezer and thaw. Centrifuge at 4250 rpm
for 45 mins in the Jouan KR422.
14. Transfer 130
ul of the supernatant from each well to a new block using the Hydra
15. Add 130 ul of
isopropanol to each well using the manual Eppendorf repeater pipette.
16. Centrifuge at 4250 rpm for 45 mins in the Jouan KR422 to
collect DNA. Decant the supernatant. Invert on a paper towel.
17. Wash with 500
ul 70% ethanol and centrifuge at 3000 rpm for 10 mins
in the Jouan KR422. Air-dry
for 10 minutes.
18. Dissolve the
pellet in 100
ul of TE-RNaseA/T1 using the Hydra followed by shaking on a table top
microtiter shaker at speed of 5 for 5 minutes to dissolve the DNA.
19. Add 50 ul
of 7.5 M of KOAc*** using Eppendorf repeater pipette and freeze at -80oC
overnight.
20. Remove the
blocks from the freezer and thaw.
Centrifuge at 4250 rpm for 45 mins in the
Jouan KR422.
21. Transfer 100
ul of the supernatant using the Hydra.
22. Add 100 ul of
isopropanol and centrifuge at 4250 rpm for 45 mins in
the Jouan KR422..
23. Wash with 500
ul 70% ethanol twice and dissolve the DNA in 20 ul sdd-water.
24. Typically the yield is about ~5 ng/ul
final 20 ul solution or 100 ng / well (800 ng/8 wells).
Notes:
* We typically
inoculate all 8 wells in a column with a single BAC and 12 BACs per 96 well
plate.
**
TE-RNaseA/T1 is 40 ug/ml RNase A and 40 U/ml RNase dissolved in 50:10 TE buffer where DNase-free RNase A was
diluted from a 20 mg/ml RNase A stock solution in 1 mM NaOAc, pH 4.5; Sigma
R-5500 and
40 U/ml RNase T1 was diluted from a 100 U/ul iRNase T1 stock solution in 50 mM
Tris-HCl, pH 7.6; Sigma R-8251**
***7.5 M KOAc
Stock Solution: 736.13 gm/liter final volume - Starting with a small volume of
dd-water (approximately150ml) slowly add the dry potassium acetate and mix as
it is added. Then add additional water and the remainder of the acetate until
all is dissolved and the final volume is 1 liter. DO NOT ADJUST THE pH as the
acetate will come out of solution.