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Dec
18
comment Cells scatter light in solution. Do they refract?
Scattering alone contributes to turbidity. Absorbance just causes attenuation of the amount of light (measured in flux) passing through the sample. The light coming out the other side is dimmer than what went in.
Nov
18
comment Predictive Single Nucleotide Polymorphisms (SNPs) for Bipolar Disorder
Yes, that's what I mean.
Nov
13
comment What are the features on a microscope one needs in order to do lab work?
Keep in mind that you will need it to have a camera to store the images, at least in a clinical or research setting. That will add quite a bit more expense. If you get creative, you can now use smartphone cameras for much less.
Nov
5
comment Food allergen-related skin reactions and intestinal inflammation?
I don't know for certain that is the causal direction, but that is the direction I was intending when considering that immediate contact with the food allergen initiates an allergic reaction, so it may stand to reason (I'm not an immunologist), that if the food is ingested, may then later cause gastrointestinal problems.
Nov
5
comment Food allergen-related skin reactions and intestinal inflammation?
Oh, I see what you did then. No harm done.
Nov
4
comment Food allergen-related skin reactions and intestinal inflammation?
I don't see how that question is related. It deals with extra-intestinal diseases, of which, dermatologic conditions may be a subsequent symptom. This question deals with the reverse direction of causation. Skin contact -> intestinal issues.
Oct
28
comment Why is coffee a laxative?
It's not valid to compare anecdotal (or real, for that matter) effects of those drugs you mention to a specific effect of caffeine just because they are broadly classed as stimulant drugs. Those two drugs all have distinct mechanisms of action to how they work. However, if they increase gut motility (e.g., peristalsis) then it may coincidentally also increase defecation.
Sep
26
comment Death because of distilled water consumption
Sorry, I took the question to mean drinking distilled water only, and ingesting nothing else. I entirely agree that my previous answer was misleading, and @recurivelyironic and TonyH give much better answers for acute effects or drinking distilled water while still eating normally.
Sep
23
comment Troubleshooting SDS-PAGE of trypsin-treated BSA
The stacking gel should be 4%, and the separating gel is usually no greater than 16% (and that's to separate really large proteins). What molecular range bands are you expecting to see, and why is the separating gel percentage so high?
Sep
21
comment How can I determine the purity of cells isolated from rat brains if I cannot use FACS, Immunohistochemistry or SEM anaysis?
@WYSIWYG - I agree, but that means the technique is not only qualitative. Automated imaging and segmentation is the modern successor to random fields + stereology.
Sep
20
comment Machine learning for light microscopy — problems to solve?
Blind deconvolution is already a Bayesian algorithm of sorts. Scaled-gradient-projection deconvolution is a faster computational approach leading to similar or better increase in resolution. It's currently applied to optical microscopy and could be extended to super-resolution microscopy.
Sep
20
comment Machine learning for light microscopy — problems to solve?
Look into WEKA segmentation algorithms implemented in FIJI/ImageJ.
Sep
20
comment How can I determine the purity of cells isolated from rat brains if I cannot use FACS, Immunohistochemistry or SEM anaysis?
q-PCR would be the most accurate PCR technique if you wanted a breakdown of the population by percentage. Simple optical techniques are quantitative if you abide by stereology techniques.
Aug
30
comment How does extracellular potassium ion concentration and calcium ion concentration affect the excitability of a cell?
Rory M - that's not always true about decreasing excitability. Case and point: > 25 mM K+ is a standard depolarizing agent in cell culture that triggers action potential firing. Also, a high K+ gradient across the membrane still leaks some K+ into the cell. Strictly speaking, this depends on the complement of voltage-gated and voltage-insensitive ion channels expressed on the cell surface.
Aug
30
comment Does scratched Teflon coated frying pans contain carcinogens which can cause cancer?
Hi there, I've tried to re-word your question to be more objective about the concern that Teflon (or some part of the pan) may contain possible carcinogens. I hope you are happy with this edit.
Jul
31
comment Verifying Protein Folds
That is what happens. These distributed computing platforms send out duplicate jobs for computation and the results compared after all are returned. It is also possible to get a sense of confidence in the fold prediction by comparing sequence homology to what is already known for solved protein structures.
Jul
4
comment FRET only works for interactions between 1nm to 20nm.
That's also true, I assumed the discussion of proteins.
Jul
3
comment FRET only works for interactions between 1nm to 20nm.
While this is true, FRET is not a fool-proof experimental approach, and can give either false positives or false negatives. I think Bioguy wants a way to confirm FRET results.
Jul
2
comment Kinesin-5 / cytoplasmic dynein spatial density distribution in neurons
Are you sure that GFP tagged motors don't function properly in these two cases? I'm almost certain I've seen motors tagged before.
Jun
30
comment What equipment would one use to modify a virus?
It's not clear the biological purpose for how you want to modify a virus. As WYSIWYG suggests, the genome is one way, but it is also possible to modify a the external capsid of a virus and give it new function (think targeting a virus for chemotherapy).