| a very specific request |
[26 Jul 2008|08:31am] |
At my company, among other things, we make Master Mixes and dNTP blends and stuff like that for PCR. We made one dNTP blend recently, and would consistently get no PCR product when tested. During troubleshooting, we ran it on HPLC and found there was no peak for G, and a correspondingly larger peak for T/U.
Here's the problem. The blend has both T and U in it already, and of course our operators have access to both already also. Is there another analytical test that can be performed to resolve whether it's T or U? (We're also doing inventory verification, but so far that's been inconclusive.)
Any advice would be much appreciated.
(x-posted)
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| Question |
[25 Jul 2008|11:02pm] |
Does anyone by any chance know the pKa (acidity) of benzylamine or phenylethylamine? I have gone through hundreds of pKa tables and just cannot find this value. I'm guessing it's probably around 32 or something, but I need to know for certain.
Thanks!
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| Weird SDS-PAGE problem |
[23 Jul 2008|05:03pm] |
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Hey everyone. I am curious to know if anyone here has had a similar problem to mine and what steps were taken to resolve this problem. After pouring resolving (gradient) and stacking gels and allowing them to polymerize, I proceed to unclamp everything and remove the gasket from around the glass plates. However, on some occasions when removing the clamps, air seems to get sucked in from the sides and bubbles get trapped in the interface between the stacking and resolving gels. They are almost impossible to push out and ruins the gel. This does not happen every time that I pour these. In fact, it seemed that I had solved the problem by removing the comb first, and then unclamping the glass plates. This worked for 0.75 mm gels, but when I moved up to 1 mm gels the problem appeared again. Much thanks for anyones help!
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[22 Jul 2008|08:24pm] |
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Does anyone know where I can get hooked up with a cheap vacuum pump, suitable for bench-top vauum filtration?
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[22 Jul 2008|08:22pm] |
Hello, long time lurker first time poster.Two questions:
1)Anybody know where I can find "/glnx86" library for Matlab 7.5?We're running 64-bit in the lab and it's making 3 different shades of trouble, so of course in addition our /glnx86 library is missing for some reason so we can't run it as 32-bit.:(
2)I'm nearing the end of my B.Sc. and am looking into Ph.D. in neurolinguistics- anybody can recommend a researchers to study under?
Thanks in advance.
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| startups, cell culture, etc |
[21 Jul 2008|12:01pm] |
Hi Everyone, I posted this thread http://community.livejournal.com/_scientists_/1065381.html a couple months back and just wanted to follow up that I did take the job, and the advice I got from this community was helpful. I have learned a lot and gained lots of bench work experience. It is extremely challenging since when things get screwed up, it's usually my fault. (If anyone has any questions about working at startups or my experience, I think I can answer them now)
So my next question is regarding cell culture. In the last few weeks I have had some issues with my HeLa cells, and pretty much all the cells in the incubator getting contaminated. Though it's probably something I'm doing wrong, I really really hope it is something else.
Does anyone have any cell culture horror stories? has anyone lost their job based on this? I'm feeling super jittery now. Maybe I'm just not cut out for this. Anyone?
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| qPCR primers; dimers and delta G |
[21 Jul 2008|11:45am] |
| [ |
mood |
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 puzzled |
] |
So I'm trying to design primers for quantitative (real time) PCR of some chicken cytokine mRNAs using Vector NTI, and especially with the IL-2 gene I am not finding any ones that look very good. The gene is pretty AT rich, so the primers have to be a little longer (23-25 bp) so as to have the right melting point, and they *all* are predicted to make dimers and hairpin loops. Many of these structures have a *positive* delta G, though, as predicted by Vector. My advisor says that it dosen't matter; I need to find ones without hairpin loops (though dimers can be managed). I thought a positive delta G was energetically unfavorable? Are these structures really likely to happen? Ho do you deal with a gene that seems to just not have good primers?
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| Article request |
[18 Jul 2008|08:40am] |
Can anyone help me with the pdf of this article?
Link
Thank you so much in advance ;)
shylaughter at gmail dot com
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| New Website |
[17 Jul 2008|10:09pm] |
I've made a website for my TATA box t-shirt: http://tatabox.freeshell.org and you can now email me at tatabox@freeshell.org. It's hosted by the Super Dimension Fortress, which offers free UNIX based hosting.
I will be printing a second batch of shirts, this time with more L's and XL's, that will probably be ready by next week. You can check for updates on my site. Thanks for all your nice comments ! :)
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| Article request? |
[15 Jul 2008|02:10pm] |
Does anyone have access to this article that they could send to me? Thanks in advance! :)
Class IA phosphatidylinositol 3-kinase: from their biologic implication in human cancers to drug discovery.
Maira SM, Voliva C, Garcia-Echeverria C.
Expert Opin Ther Targets. 2008 Feb;12(2):223-38.
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[15 Jul 2008|08:51am] |
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I am considering postdocs outside of the US (my country of citizenship). Have any of you guys done postdocs outside your country of origin? What are the pros/cons of this situation? Are there questions I should ask my potential boss to make this process easier?
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| TATA box shirts |
[14 Jul 2008|10:53pm] |
Hi guys,
I posted a couple months ago with my TATA box "I wish I were a DNA helicase so I could unzip your genes" t shirt and some of you guys said you liked and and might be interested in buying it.
So I drew it on Illustrator and printed a few:
( The t-shirt design )
( How it looks when worn )
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| Article request |
[14 Jul 2008|02:05pm] |
Does anyone have access to this article and would be able to send me a copy?
J Autism Dev Disord. 2006 Nov;36(8):973-82.
Utilization of lymphoblastoid cell lines as a system for the molecular modeling
of autism.
Baron CA, Liu SY, Hicks C, Gregg JP.
If you can find it please send it to chemrocks04@yahoo.com
Thank you <3
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| medicated scientists |
[13 Jul 2008|03:20pm] |
Just a simple curiosity. How many scientists on here have been diagnosed with A.D.D (Attention Deficit Disorder) and take medication whether they are SSRI's (Dexadrine, Etc) or NRI's (Strattera, Wellbutrin, Etc) and have a successful career or position in research and development or at a lab?
If it is not you personally but know of an anecdote of someone else please share.
Cheers,
Alexzander
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| Article request-EMERGENCY. |
[13 Jul 2008|12:07pm] |
I need this article as soon as anyone can get it. It's for my preliminary examination and pretty much determines if I pass or not. :(
Durham, D. G. et al. Chlorination of Pyrroles. III. Canadian Journal of Chemistry (1972), 50(19), 3223-8.
pokechokey at hotmail dot com.
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| HELP!! |
[13 Jul 2008|05:44pm] |
Dear clever generous wonderful scientist.
Here i am at work on a sunday getting a sequencing reaction cleaned up for tomorrow when I accidentl added 70% EtOH not 100%
Here are the details
1uL Big Dye 3.1
3.5uL 5 buffer
3.2uL SP6 primer (for pGEM vector)
12.3uL DNA
Clean up
5uL 125mM EDTA
60uL 100% EtOH
At this step I added 70% not the 100%.
Leave to incubate at RT for 15 min
30min spin
wash with 70% EtOH
dry pellet
Is this going to eff up my sequencing tomorrow?
Please tell me some good news?
Sincerely
Zena
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| sources for protected unnatural amino acids |
[12 Jul 2008|04:30pm] |
Does anyone here do/has done solid phase peptide synthesis?
If so, which suppliers did you order protected amino acids from? And do they sell unnatural or modified amino acids? Specifically I want to make peptides with phospho-Ser/Thr, methionine sulfoxide, and 3-nitrotyrosine. Sure, I can do wet chemistry on the peptides after they're synthesized, but it would be nice to have modified amino acids to start with so I don't have to worry about side reactions.
I imagine phosphoserine/phosphothreonine would be available, but I've never heard of anyone making peptides with oxidized methionine or nitrated tyrosine.
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