# Converting solution concentrations

• Jul 28th 2012, 01:09 PM
LuluNeedshelp
Converting solution concentrations
How do I convert 1,000,000 copies per 5 microliters to copies per milliliter?
• Jul 28th 2012, 01:46 PM
emakarov
Re: Converting solution concentrations
There are two methods: using common sense and using dimensions. For common sense, answer the following questions.

(1) Since 5 microliters contain 1,000,000 copies and 1 microliter is 5 times smaller than 5 microliters, how many copies does 1 microliter contains?

(2) Since 1 milliliter is 1000 times bigger than 1 microliter, how many copies does 1 milliliter contain?

For dimensions, we know that there are 1000 μl per ml. How to combine $\displaystyle \frac{1,000,000\,\text{copies}}{5\,\mu l}$ and $\displaystyle \frac{1000\,\mu l}{1\,ml}$ to get copies as the answer? It's $\displaystyle \frac{1,000,000\,\text{copies}}{5\,\mu l}\cdot \frac{1000\,\mu l}{1\,ml}$; then μl cancels out to leave $\displaystyle \frac{\text{copies}}{ml}$.
• Jul 28th 2012, 02:57 PM
LuluNeedshelp
Re: Converting solution concentrations
Obviously I don't have common sense, so thanks for the dimensional help!

Ok, so just to make sure I've got this right...

The answer I got was 200,000,000 copies per mL

Thank you so much for your help...my math brain has been dormant for a very long time!

Much appreciated!
• Jul 28th 2012, 03:01 PM
emakarov
Re: Converting solution concentrations
Quote:

Originally Posted by LuluNeedshelp
Ok, so just to make sure I've got this right...

The answer I got was 200,000,000 copies per mL

That's correct.