Many thanks for your rapid inputs.
We used to make glyerol stocks but now we do not since the protein
expression is not stable. Our lab is about 10 students, who have to
make their own proteins so our three large-scale shakers are very
crowded every day. We did try a formaldehyde gas treatment one time
during our new year leave, however, the situation did not seem to
improve. Since that gas is much harder to handle, we only stick to
ozone treatment. Intriguingly, our neighbor lab, also a
crystallography lab, which constantly uses bacterial cultures although
not as much as we do, is just fine.
Chloroform/phenol treatment might be a good one because some of our
constructs are just very difficult to get any transformed colonies
while some others are so easy. We have used gel extraction method to
purify our plasmids because we thought some phage DNA is contaminated.
This method slightly improved our situations but not complete. But I
am thinking the entire phages are simply there in plasmid preps
purified through miniprep columns.
Cheers
Aidong
On Mar 2, 2013, at 7:30 PM, DUFF, Anthony wrote:
Hi Aidong,
some ideas...
Do you use glycerol stocks of transformed expression cells (phage
risk), or do you do fresh transformations each time?
Do you have many people working together, or do you have periods of
bacterial growth separated by periods of inactivity?
Do you have neighboring labs who may be working with, or infected with
phage?
Do you have any old stocks, liquid media, antibiotics, etc, that could
be contaminated?
sincerely,
Anthony
________________________________________
From: CCP4 bulletin board [[email protected]] on behalf of aidong [[email protected]
]
Sent: Saturday, 2 March 2013 7:50 PM
To: [email protected]
Subject: [ccp4bb] laboratory phage infection
Hi All,
Really sorry for my non-CCP4 related question. Our lab mainly uses
bacterial cultures to produce targets proteins for crystallizations.
However, we have been struggling with phage infections to our
bacterial cultures for a quite long time. To control its devastating
effects, we have regularly been using large-dose ozone treatments on
the whole lab space. We have also tried anti-phage BL21/DE3 strains
from Sigma USA but found it was still not avoidable. The lab has been
maintained well hygienic and its outdoor environment is clean and
neat. We keep good ventilations, including windows and central AC
systems. However, phages are still eating up our cultures with very
low percentage of survivals. Therefore, this has been our big
headache. We wonder whether you have the same experience and how to
keep a lab free of those bugs. Your suggestions are deeply
appreciated. Thanks.
Sincerely
Aidong
Aidong Han, Ph.D
Department of Biomedical Sciences
School of Life Sciences
Xiamen University
3 South Xiangan Road
Xiangan, Xiamen 361102
China
Phone: 0592-218-8172 (O)
0592-218-8173 (L)
Web: http://life.xmu.edu.cn/adhanlab/
Aidong Han, Ph.D
Department of Biomedical Sciences
School of Life Sciences
Xiamen University
3 South Xiangan Road
Xiangan, Xiamen 361102
China
Phone: 0592-218-8172 (O)
0592-218-8173 (L)
Web: http://life.xmu.edu.cn/adhanlab/
