Well, it's just a word of advice. Don't blame me if somebody gets your nice mathematical notation wrong and screws up your experiment. If there is a simpler (also mathematically correct) way to put things down, why not use that one? The example of the thread-starter shows how things can go wrong in real life, even if you do everything right.

Update: MKR, that is not entirely true. I remember that in primary school we used colon (:) as a mathematical notation of division. And (surprise, surprise!) Wikipedia says:
In that case, it does not mean a to b. Therefore you can not even tell those people to go back to elementary school, because even if they did, they'd learn the same thing again :D

From the above link we can also learn, that (compare a∶b with a:b) But that still may be a bit risky to use :D

---

Now we've got 3 dots between numbers! That's why once you leave elementary school you should never go back!

Give a hoot, don't dilute! No more stock solutions, only solutions.

---

When using the 2X 10X 100X, you have to be very careful though. In my experience this system is mostly used for stock solutions. That is a 10X is to be diluted ten times to produce a 1X solution which would be used in a reaction. In general I am for completely specifiying whatever mix is to be done (especially by someone else, but also by me). If you write "mix 1ml of stock solution with 2ml of PBS" or "1ml 3X stock + 2ml PBS" you can be rather certain to understand your own notes after ten years or so.

/M

---

Hi,
If we place the word "ratio" in x:y, then there won't be any confusion, right? Better than x:y "dilution" because don't really know if x is being diluted by y or y diluted by x.

I'd prefer to phrase it as "ratio of x:y", "x:y ratio", or "solution A: solution B = x:y" or "A:B:C=x:y:z".

Just leave dilution as 100 X diluted meaning if Y is the volume (or part) of solution we have, it'd blown up to 100Y volume with a solvent (or diluent).

Or 1Y/100Y dilution meaning we have 1Y volume of solution in a total volume of 100Y. Where Y is a variable.

---

I have learned at school (2 different countries, both in Europe):

1:5 means 1/5 means 1 divided by 5, means one 5th of total amount.
And that's why I would always consider 1:5 as 1 part of 5 meaning take 1 and add 4 to a total of 5.
As simple as that
Pure mathmetics

Kahlan

---

I guess I was the only one to learn ':' was different than divide. No wonder people think I'm slow, it's because I was quick to learn the wrong thing. So actually I am smart, I just learned the wrong stuff to be considered smart

---