Search found 15 matches

by keetner
Sat Mar 15, 2014 3:21 am
Forum: Molecular Biology
Topic: Help: Confused with primers in a PCR of a vector?
Replies: 2
Views: 9113

Help: Confused with primers in a PCR of a vector?

Hi guys, I am an undergrad being introduced to a lot of different lab techniques, so I'm not entirely familiar with what is going on. We recently ligated a gene into a pBS vector and popped it into some E. coli cells. We looked for positive clones via blue/white screening and isolated/purified the r...
by keetner
Sat Dec 15, 2012 2:28 am
Forum: Molecular Biology
Topic: ETC - purpose of having different dehydrogenases?
Replies: 1
Views: 5707

ETC - purpose of having different dehydrogenases?

Hey guys, There's something I'm a bit confused by. I've been reading about how E. coli can have different NADH dehydrogenase complexes (more specifically, NDH-1 and NDH-2). One major difference between the two is the fact that NDH-1 is a coupling site (so pumps out protons while transferring electro...
by keetner
Thu Nov 29, 2012 3:24 am
Forum: General Discussion
Topic: Can particle size affect spectrophotometry?
Replies: 1
Views: 2384

Can particle size affect spectrophotometry?

Hey guys, I'm not sure where else to put this...doesn't seem to fit anywhere else. But if you have a lipid sample in a cuvette, I know that changing the concentration will affect the absorbance readings. But what about particle size? For example, I was working with two different lipids (phosphatidyl...
by keetner
Thu Nov 01, 2012 5:16 am
Forum: Molecular Biology
Topic: Spectrophotometry - why can't some products be read?
Replies: 2
Views: 5232

Spectrophotometry - why can't some products be read?

Hi folks, I'm reading about this coupled reaction between hexokinase/glucose-6-phosphate dehydrogenase in regards to spectrophotometry. The reaction I'm given is: glucose + ATP ----(hexokinase)---> G-6-P + ADP G-6-P + NADP+ <---(G-6-P dehydrogenase)---> 6-phosphogluconolactone + NADPH The above is j...
by keetner
Thu Oct 25, 2012 6:09 pm
Forum: Microbiology
Topic: How does pH change during sporulation? - Help
Replies: 2
Views: 4071

Ah, yes! I managed to find a few articles in regards to acetate production (or I guess acetic acid). Which would make sense, cause then it could go into the TCA cycle (where rise in pH likely occured).

Thanks for the response either way =).
by keetner
Mon Oct 22, 2012 10:22 pm
Forum: Microbiology
Topic: How does pH change during sporulation? - Help
Replies: 2
Views: 4071

How does pH change during sporulation? - Help

Hi folks, I carried out an experiment where I observed sporulation in a Bacillus species. The bacteria was innoculated in this medium that contained a bunch of salts, glucose, and ammonium acetate. Every few hours or so, we were required to take the pH of the sample. My results: Between T = 0 to 8 h...
by keetner
Mon Oct 08, 2012 6:57 pm
Forum: Off Topic Discussion
Topic: Last person to reply wins.
Replies: 8431
Views: 2402229

Ha, this is kind of funny. I wonder what the limit to threads are...
by keetner
Mon Oct 08, 2012 6:53 pm
Forum: Molecular Biology
Topic: Calculating the molecular concentration of DNA
Replies: 6
Views: 9785

Re: Calculating the molecular concentration of DNA

Ahh, I get it. That's what I was thinking. You basically summed up my messy post in two short sentences.
Thanks again for the help + clarification you guys :).
by keetner
Mon Oct 08, 2012 12:23 am
Forum: Microbiology
Topic: gram negative cocci. please help
Replies: 8
Views: 16288

You said you did an ACID FAST test to show you if it was GRAM NEGATIVE? Did you do a Gram stain at all? An acid-fast test doesn't tell you if it's Gram negative or Gram positive. Rather, it's an alternative test if your Gram stain doesn't work (of if you're unsure of results) to test if it has a cra...
by keetner
Sun Oct 07, 2012 11:11 pm
Forum: Molecular Biology
Topic: Calculating the molecular concentration of DNA
Replies: 6
Views: 9785

Re: Calculating the molecular concentration of DNA

Hrm... I think the (gram/mol)/bp is throwing me off. With dsDNA, it's 660 but with ssDNA, it's 330. Also, I think I was under the impression that if you had the MW of a base pair in DNA, you would divide that MW in half so you could get the MW of each base. Though I guess that would make no sense si...
by keetner
Sun Oct 07, 2012 8:13 pm
Forum: Molecular Biology
Topic: Calculating the molecular concentration of DNA
Replies: 6
Views: 9785

Thanks for the response! I'm still confused as to why you would multiply by two (my second question). If 660 is the mass of the base PAIRS, I assume we are including the mass of both strands. So to me, before we multiply by two, the mass of a double strand DNA would be ~3.29x10^-11. It's confusing b...
by keetner
Sun Oct 07, 2012 7:49 pm
Forum: Molecular Biology
Topic: Calculating the molecular concentration of DNA
Replies: 6
Views: 9785

Calculating the molecular concentration of DNA

I'm not sure if you guys will be able to help me or not...but I thought I would at least try posting: http://i.imgur.com/jlq9T.jpg In case the image is cut off: m 1) Look at the 660g/bp (it means g/mol of base pair); it is highlighted in pink - I do not understand where this 660 is taken from. Some ...