Search found 440 matches

by jonmoulton
Mon Jan 27, 2014 10:44 pm
Forum: Cell Biology
Topic: centrifugation of hemocytes
Replies: 5
Views: 11458

Re: centrifugation of hemocytes

Are you resuspending in a PBS solution isotonic to the cells? Lysis could explain why the cells aren't there. You could try slightly increasing the tonicity of the PBS - better to have crenated cells than lysed cells.
by jonmoulton
Thu Jan 16, 2014 9:46 pm
Forum: Molecular Biology
Topic: blank and substrate control give OD reads
Replies: 9
Views: 12501

Re: blank and substrate control give OD reads

Here's another approach. Set up a pair of tubes identically, containing everything but the xylanase. Check their OD. Add xylanase to one of the tubes and mix. Check the OD again. That way you control for other potential errors, such as a difference in buffer concentration or a variation in tube thic...
by jonmoulton
Thu Jan 16, 2014 3:23 pm
Forum: Molecular Biology
Topic: blank and substrate control give OD reads
Replies: 9
Views: 12501

Re: blank and substrate control give OD reads

Is there anything in the buffer that absorbs light at the wavelength you are using for your OD readings? It might be worth running the buffer in a spectrophotometer and comparing against water at wavelengths near your OD measurement.
by jonmoulton
Thu Dec 05, 2013 4:27 pm
Forum: General Discussion
Topic: Reasons why spontaneous human combustion is impossible?
Replies: 10
Views: 12381

Re: Reasons why spontaneous human combustion is impossible?

Thank you Jack, I enjoyed riding along with your calculations. Coelacanth, your idea that the effect of water is lessened because only the skin is an issue for combustion is an interesting hypothesis. I'm not ready to expect spontaneous human combustion until I have seen reliable documentation, but ...
by jonmoulton
Tue Dec 03, 2013 4:07 pm
Forum: General Discussion
Topic: Reasons why spontaneous human combustion is impossible?
Replies: 10
Views: 12381

Re: Reasons why spontaneous human combustion is impossible?

It would be interesting to calculate the energy released if all the body's nucleotide triphosphates (e.g. ATP) were to simultaneously hydrolyze. I see no mechanism for that happening, but that should represent a pretty good stock of potential energy.
by jonmoulton
Fri Nov 22, 2013 4:53 pm
Forum: Microbiology
Topic: Coral mushroom
Replies: 1
Views: 3742

A 10% solution of ferrous sulfate tinted the mushroom's tissue greenish at the tips, confirming the genus Ramaria. So far I've tried it sauteed with butter and garlic and also stir-fried with bitter melon. Both preparations were delicious.
by jonmoulton
Fri Nov 22, 2013 4:49 pm
Forum: Microbiology
Topic: URGENT HELP IDENTIFYING UNKNOWN BACTERIA!!!
Replies: 7
Views: 25860

Re: URGENT HELP IDENTIFYING UNKNOWN BACTERIA!!!

Looks like a job for Bergey's Manual of Determinative Bacteriology.
by jonmoulton
Tue Nov 19, 2013 10:56 pm
Forum: Microbiology
Topic: Coral mushroom
Replies: 1
Views: 3742

Coral mushroom

See attached .gif
by jonmoulton
Thu Nov 14, 2013 8:47 pm
Forum: Cell Biology
Topic: Cyanobacteria to bacteria
Replies: 4
Views: 5422

Re: Cyanobacteria to bacteria

...and I was sloppy. I should have written "absent in OTHER eubacteria."
by jonmoulton
Wed Nov 13, 2013 4:29 pm
Forum: Cell Biology
Topic: Cyanobacteria to bacteria
Replies: 4
Views: 5422

Re: Cyanobacteria to bacteria

Cyanobacteria have multiply-folded membranes studded with photosystems where the light reactions of photosynthesis occur. The presence of these membranes is the most obvious ulstrastructural difference shared by all cyanobacteria and absent in eubacteria.
by jonmoulton
Mon Nov 11, 2013 4:38 pm
Forum: Molecular Biology
Topic: qPCR vs Northern Blot
Replies: 4
Views: 7781

Re: qPCR vs Northern Blot

I see that I reversed the sense of the observations - the Northern signal was maintained, the PRC signal decreased. A splicing change could still produce that result, as could the RNA degradation Jack mentioned.
by jonmoulton
Thu Nov 07, 2013 10:12 pm
Forum: Molecular Biology
Topic: qPCR vs Northern Blot
Replies: 4
Views: 7781

Re: qPCR vs Northern Blot

I assume you are assaying aliquots of the same RNA samples by the two methods. Does your Northern probe bind between the binding sites of your PCR primers? If not, it is conceivable that a change in splicing in the presence of the shRNA causes your Northern target to be spliced out of the pre-mRNA w...