Tabaluga

1. Regarding your hypothesis that the cells adhere to the tube, I once had a problem with cells adhering to walls of small Eppi reaction tubes. The discussion can be found here http://www.protocol-...ing#entry147612

2. To your question specifically, do you count viable or total amount of cells ? Because depending on how senstitive the cells are to these conditions, viability may drop within 1 h so there will be a lesser amount of viable cells. I don't know if the Coulter counter automatically distinguishes viable from dead but I think the range of sizes to be measured can be defined in the settings.

Maybe by that he means that he thinks a different kind of fixation might be used...
I've no experience with DAPI in FACS, but did you see this paper ? http://jcb.rupress.o.../171/3/559.full

I don't think it's an experimental error.
First of all, how much higher are the levels than normal ? leelee's understanding is correct, there are certain cut-off values (higher than which the tumor markers are considered as elevated and thus indicate a tumor), but the extent of the elevation often plays a role. In case of PSA the value for free PSA would be interesting to know too, if it is indicated in the study.
Second, there are several factors (other than a tumor) which can induce some tumor markers - smoking can induce CA19-9, for instance. Here is a paper on non-malignant causes of CA19-9 increase:
http://edoc.hu-berli...lm.2009.152.pdf
I just wonder what was checked for (and what wasn't) when it is stated "in good health". So they try to make the point that high natural radiation increases PSA and CA19-9 ? There might be minor (possibly inflammatory) processes ongoing already which are of no clinical relevance.
Conversely, not all tumors of a certain type express the respective tumor marker at all, which is why they can only be used to control progression or remission of the disease if they were already elevated at the point of diagnosis. PSA is used for general prostate carcinoma screening, while CA19-9 cannot be used for general screening.

Hi everyone,
I checked for expression of a (surface) protein in a cell line with flow cytometry and WB. According to flow cytometry (which is well established for this protein in my lab) 40% of the cells do express the protein. According to WB (which is also well established) there is no expression.
What could explain the discrepancy ? And which result would you trust ? Honestly, I'm at a loss, it's extremely strange...

Thanks...

Hi people,
got a quick (and urgent) ImageJ question. I've measured lengths with the Line Tool and Ctrl+M (Measure). Now I got a table with values. Are these values by default in pixel or what unit are they in ? Didn't find the info via google now.

Thanks !

Is this a readcube advertisement thread now ??

pcrman, on 23 March 2013 - 02:56 PM, said:

I also print out some papers (at least those that are really important and that I want to study in more detail), however a reference manager is still helpful for organising and referencing the papers for a thesis or a paper etc.

And I also archive them in computer folders, but there I only call them like "Smith J Cell Bio 2009" because when I read a paper I always try to associate the content with the first author's name - in most cases it works fine, but could of course become increasingly difficult as the library grows

Hi people,

let's say I have a protein Y to which there is no known inhibitor, and I still want to study the effect of inhibiting it on a certain cellular process (not considering the possibility of doing a knockdown). There is however an inhibitor available of another protein X upstream in the signaling cascade, which regulates my protein Y. So if I were to inhibit the upstream protein X and could show at the same time that levels of my protein Y go down and the expected cellular process stops, would you regard this as at least a strong hint (doesn't prove anything obviously) that my protein Y is associated with this process ? Or would you say this experiment is a waste of time since the upstream protein X obviously regulates many other proteins too and thus it is "guilt by association" only ?

I'd very much appreciate your comments on whether this approach makes any sense (personally, I must say I'm not convinced), or if you have any other ideas.
Thanks!

And I just see that leelee stated the same thing in a lot less words

Agree with Bob and clinically speaking, if the IgM titre of a certain antibody is high, you can infer that the person has got a relatively fresh infection, still in its early phase, while a high IgG titre shows you that the person is either having that infection currently but not quite fresh - or had it once, built antibodies against it and is immune now.

A monoclonal antibody is raised against a specific single epitope of a certain antigen. It is called monoclonal because it is derived from a single clone of identical immune cells which are derived from a unique parent cell. Polyclonal antibody is a mixture of antibodies from different immune cells that are raised against the same antigen, but recognize different epitopes. They are not derived from a single clone of immune cells.

What do you mean by saying the ladder runs almost properly ? Is it normal or not ? If it's normal the overall electrophoresis should be working, shouldn't it ?

Unfortunately I don't know myself, but I think there are quite some people with this problem...
There are lots of discussions and suggestions all over the web: https://www.google.d...iw=1024&bih=497

For a start you could read some of these, till maybe someone comes along who can give further advice...

Another game for the Chit Chat section... Guess the quote !
Here are the rules:

1. The quotes to be guessed are from classic literature works, the work and the author should be internationally well-known.
2. The person who guesses correctly will post the next quote for guessing.
3. After 3 posts with wrong or guesses or cluelessness, the poster of the quote should give a hint.
4. Honor code - we won't type the quote into google and look for the answer this way. This is supposed to be a guessing game, and
    simply looking up the answer would spoil the fun, so please refrain from doing that.

Hope you'll join and have fun! So let's get it started with a hopefully not too difficult one :

"I do not know my age, for I have not counted the years I have been here."

Depends very much on which depth you want to analyse it in and what equipment and possibilities you have. Is it for something like a microbiology class assignment or do you want to perform a serious check ?

http://en.wikipedia...._water_analysis
http://www.epa.state...rt/microman.pdf