Search found 778 matches

by biohazard
Tue Nov 27, 2012 7:32 am
Forum: Evolution
Topic: Is evolution as simple as we think?
Replies: 41
Views: 62824

Dayren, what do you mean by there was no evolution of organisms during that time? As far as I understand, there has been evolution of organisms basically whenever there first was competition for resources or space to live, which would be pretty soon after life emerged (local competition would happen...
by biohazard
Mon Nov 12, 2012 2:04 pm
Forum: Cell Biology
Topic: Animal cell nucleus shape changes
Replies: 7
Views: 16228

Yeah, I think you can make those two assumptions. Although there are exceptions to this rule as well, like there are exceptions to almost everything in biology. For example, in many cells the nucleus also changes in shape when the cell matures. This is well evident in, for example, neutrophilic leuk...
by biohazard
Mon Nov 12, 2012 10:17 am
Forum: Cell Biology
Topic: Animal cell nucleus shape changes
Replies: 7
Views: 16228

Most cells have a well-defined nucleus especially when not in cell division. So, in my opinion that statement is false. Or at least poorly defined. Under a light microscope in a native sample the nucleus may "appear" amorphous, but it is not so in reality. 1) The shape of the nucleus is al...
by biohazard
Tue Nov 06, 2012 9:30 am
Forum: Molecular Biology
Topic: DNase I stability
Replies: 1
Views: 3267

DNase I stability

Does anyone know exactly how long DNase I stays active, when stored in 50% glycerol and in -20C (kept in liquid form to avoid freeze/thaw cycles)? Some supplier stated that their product is guaranteed to have activity > 90% after 6 months, but others simply state that "store in -20C" witho...
by biohazard
Tue Nov 06, 2012 8:08 am
Forum: Cell Biology
Topic: Are dendritic cells phagocytes?
Replies: 4
Views: 9795

Well, hmmmh. Not sure what your textbook is, but the ones I checked quite explicitly labelled dendritic cells as "professional phagocytes" - meaning that phagocytosis is one of their primary duties. You could, for example, check Janeway's Immunobiology, which is a highly regarded and widel...
by biohazard
Mon Nov 05, 2012 1:17 pm
Forum: Cell Biology
Topic: Are dendritic cells phagocytes?
Replies: 4
Views: 9795

Yes, dendritic cells are phagocytes.
by biohazard
Mon Nov 05, 2012 1:11 pm
Forum: Cell Biology
Topic: peripheral mononuclear cells handling
Replies: 3
Views: 4057

Scraping them with a pipette might be bit difficult, but if you have to use 96-well plates then that might be the only option. Or do they have mini-scrapers for so small wells? You could try seeding the cells on a bigger plate and using plastic cell scrapers after the EDTA-treatment. I have used 5 m...
by biohazard
Fri Nov 02, 2012 8:46 am
Forum: Cell Biology
Topic: peripheral mononuclear cells handling
Replies: 3
Views: 4057

Depends on what subset of PBMCs you want to study. In general, blood cells are suspension cells and do not require trypsination, but monocytes are an exception: they adhere to certain types of plastics (which includes most cell culture plates) and must be removed with PBS/EDTA & cell scraper, or...
by biohazard
Thu Nov 01, 2012 7:11 am
Forum: Evolution
Topic: Things that cause cancer (in modern humans who live longer)
Replies: 4
Views: 9094

Sorry, I wasn't being too clear. The lack of fibre is not the only "harmful" trait of red meat. But it is a factor that, if eliminated, also negates many of the harmful effects of red meat. Not all, though, but enough for most people if it is consumed in moderation. Red meat contains sever...
by biohazard
Wed Oct 31, 2012 11:05 am
Forum: Evolution
Topic: Things that cause cancer (in modern humans who live longer)
Replies: 4
Views: 9094

Unless I am mistaken, the higher rate of mutations in older parents is not linked to eating red meat. What comes to the increased cancer risk red meat, as far as I know, affects the gut epithelium and mostly increases the cancer rate in the lower digestive tract. However, mutations happening in the ...
by biohazard
Wed Oct 10, 2012 5:57 am
Forum: General Discussion
Topic: Evolution- Caminalcules
Replies: 1
Views: 4029

:D
by biohazard
Tue Oct 09, 2012 7:42 am
Forum: Human Biology
Topic: What is gluten?
Replies: 2
Views: 4004

Gluten is a molecule formed by gliadin and glutelin. Normally people can process gluten without problems and it is a normal component of human nutrition. In some people with certain human leukocyte antigens (HLA) and predisposing genetics gluten may bind on the HLA molecules and initiate an autoimmu...