survival rate

[jwlapidus]

Hi

 

I'm a Bsc Microbiology student and I have to do graph with the % survival vs time.

 

But I don't know how can I do this. I have counts for three replicas at different times.

 

How can I accomplish this? How can I calculate the % survival?

 

Thank you in advance.

[Olinguito]

Try plotting the graph with the % survival on the vertical axis and time on horizontal axis. In such questions time is usually the independent variable and so is plotted on the horizontal axis.

 

Also in such questions, if you have to calculate anything, there is usually a formula you have to use. What’s the formula relating % survival and time?

[jwlapidus]

First of all, thank you for your reply.

 

My doubt is exactly that. How can I calculate the % survival? I don't have any formula. I thought that I've to subtract my final count to the previous count and then multiply for 100, but I don't know if this is accurate.

[Olinguito]

I thought that I've to subtract my final count to the previous count and then multiply for 100, but I don't know if this is accurate.

I’d say this was correct.

[jwlapidus]

I’d say this was correct.

 

Thank you

 

But I've values higher than 100%, is this possible?

Edited September 3, 2013 by jwlapidus

[Olinguito]

Oops! I beg your pardon. I didn’t think clearly. You don’t need to subtract (that would be finding the death rate, not survival rate). You just divide the final count by the original count and then multiply by 100.

The forumula is:

[latex]\text{percentage survival rate}\ =\ \frac{\text{final count}}{\text{original count}}\times100\%[/latex]

Edited September 3, 2013 by Olinguito