• Create Account

Submit your paper to J Biol Methods today!

# cell concentrations

4 replies to this topic

### #1 jsnts

jsnts

member

• Members
• 2 posts
0
Neutral

Posted 11 November 2009 - 06:35 PM

I am having some problems with determing the cells concentration.

To start i have some cells with a concentration of 9.7 x107/ml.
I took 2ml of these cells and added 1ml of media to them.
What is the concentration?

If i then take iml of the above diluted cells and add a further 0.5ml of media what is the concentration of these cells now?

jay

### #2 HomeBrew

HomeBrew

Veteran

• Global Moderators
• 930 posts
16
Good

Posted 11 November 2009 - 07:25 PM

To start i have some cells with a concentration of 9.7 x107/ml.
I took 2ml of these cells and added 1ml of media to them.
What is the concentration?

(9.7 x 10^7 cells times 2) divided by 3 ml.

If i then take iml of the above diluted cells and add a further 0.5ml of media what is the concentration of these cells now?

((9.7 x 10^7 cells times 2) divided by 3 ml) divided by 1.5 ml.

### #3 microgirl

microgirl

Veteran

• Active Members
• 122 posts
0
Neutral

Posted 12 November 2009 - 11:31 AM

I am having some problems with determing the cells concentration.

To start i have some cells with a concentration of 9.7 x107/ml.
I took 2ml of these cells and added 1ml of media to them.
What is the concentration?

If i then take iml of the above diluted cells and add a further 0.5ml of media what is the concentration of these cells now?

jay

(9.7*10^7)(2)=(C2)(3)
C2=6.5*10^7

Then do your next calculation from that.

### #4 jasmine0507

jasmine0507

member

• Active Members
• 10 posts
0
Neutral

Posted 25 February 2010 - 12:11 PM

@ microgirl.. thx.. this was easy to do.

@ Homebrew : I havent understood how have you calculated this below ? Can you explain me please, more importantly the second calculation. I haent understood it. Thank you

QUOTE (jsnts @ Nov 11 2009, 09:35 PM)
To start i have some cells with a concentration of 9.7 x107/ml.
I took 2ml of these cells and added 1ml of media to them.
What is the concentration?

(9.7 x 10^7 cells times 2) divided by 3 ml.

QUOTE (jsnts @ Nov 11 2009, 09:35 PM)
If i then take iml of the above diluted cells and add a further 0.5ml of media what is the concentration of these cells now?

((9.7 x 10^7 cells times 2) divided by 3 ml) divided by 1.5 ml.

### #5 HomeBrew

HomeBrew

Veteran

• Global Moderators
• 930 posts
16
Good

Posted 25 February 2010 - 01:57 PM

@ Homebrew : I havent understood how have you calculated this below ? Can you explain me please, more importantly the second calculation. I haent understood it. Thank you

Your original concentration is 9.7 x 10^7 cells per ml. You took 2 ml of that, thus you now have 9.7 x 10^7 times 2, or 1.94 x 10^8 cells. You added 1 ml of media to them, so now the 1.94 x 10^8 cells are in 3 ml of volume, thus the concentration in cells per ml is 1.94 x 10^8 cells divided by 3 ml, or 6.47 x 10^7 cells per ml.

Using similar reasoning for the second step, you start with 1 ml of a culture at 6.47 x 10^7 cells per ml (arrived at above, by solving (9.7 x 10^7 cells times 2) divided by 3 ml), and add 0.5 ml of media to that. Thus, you now have 6.47 x 10^7 cells in 1.5 ml of volume, and the concentration is 6.47 x 10^7 cells divided by 1.5 ml, or 4.31 x 10^7 cells per ml.