# Using cell concentration [closed]

I am doing an experiment in which I plate for example 3x10^5 cells, and every day I have to count the cells growing. I find the number and a convert it in x10^5. In my graphs I have to use the cell concentration. I am not sure which units are used for cell concentration. Is it ml, μl or anything else?

## closed as off-topic by David, Amory, Bryan Krause♦, kmm, theforestecologist♦Feb 16 '18 at 2:31

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• This site is for questions about biology. Your question is a basic question about units which you could find by an internet search. The units you cite are units of volume. You have my sympathy if you don't know what concentration means but you'll have to find out elsewhere. – David Feb 13 '18 at 19:40
• Use cells/mL, I find it easier to discuss that way. Also look at it like this: Cells grow exponentially, so you can express your concentration axis on a log scale. – CKM Feb 13 '18 at 20:16
• @David Thank you but you could answer more politely:) – Claudia Feb 15 '18 at 19:42

What is a concentration

A concentration of cells is the number of cells per unit of volume.

You are free to choose the units you like

It is very much up to you to chose the units you want as long as they express a concentration. There is no right or wrong.

You can express your graph in cells per liter or in 100,000 cells per $\mu$l or in billions of cells per ml, all would be correct. Of course, some are more intuitive than others. I would advice you to avoid expressing in cell per square meter or in billions of cells be nanoliter because the numbers will be very small and very large respectively and will not convey much intuition.

A good intuitive unit

I don't know what kind of concentration you have in you data but a priori, I would recommend expressing your concentration in cells/ml is quite intuitive.

• Really! If you respond to this sort of question the site's quality standards may not be met any longer – David Feb 13 '18 at 19:41
• Yes, I agree with @David. Not every question deserves an answer. – LinuxBlanket Feb 14 '18 at 8:52
• Every question deserves an answer please think out of the box!:) – Claudia Feb 15 '18 at 19:43
• @Claudia In fact, not every question deserves a question. Some questions that are too broad, unclear, not about biology, do not show any effort and others are typically considered as off-topic and should be closed here. I personally considered your question very introductory and by its nature only remotely related to biology but I'd have a hard time to imagine where you'd ask your question otherwise, so I decided to answer it. But it was a little bit of a limit case in my opinion. Anyway, if you think I've answered your question, you can click on the check mark. – Remi.b Feb 16 '18 at 0:49
• @Claudia btw, it is usual to get its question closed when you arrive on stackExchange. It takes a bit of time to learn the rules here. Welcome to Biology.SE. – Remi.b Feb 16 '18 at 0:50