10 millimolar (mM) to 250 micromolar - (Aug/28/2012 )
Your calculation is correct only if you plated 100 uL of your dilution.
2.5*10^9 CFU/mL * X uL of this = (uL final solution+X uL that you add on top) * 10^6 CFU/mL. Solve equation for X inserting the amount needed for your experiment in uL. It is a simple dilution from stock solution problem (c1*V1=c2*V2)
Andreea
Am little bit confused...Could you please do sample calculation ( From this step I am quite confusing from the last few days)
ascacioc on Tue Aug 28 19:49:31 2012 said:
Your calculation is correct only if you plated 100 uL of your dilution.
2.5*10^9 CFU/mL * X uL of this = (uL final solution+X uL that you add on top) * 10^6 CFU/mL. Solve equation for X inserting the amount needed for your experiment in uL. It is a simple dilution from stock solution problem (c1*V1=c2*V2)
Andreea
Do I need to dilute it down?
For which final volume? Let us assume you want to have final volume 2 mL for your experiment. You pipette 2 mL = 2000 uL of saline/media whatever.. to which you add X uL of your bacteria at OD600 = 0.4; X being the solution of the below:
2.5*10^9 CFU/mL * X uL of this = (uL final solution+X uL that you add on top) * 10^6 CFU/mL (get rid of the extra zeroes)
2500x = 2000 + x
x = 2000/2499 uL (even though I wouldn't add this little amount < 1 uL) I would do some dilution series before, something like 1 to 100 in order to add 100 times the X volume.
Andreea
ascacioc on Tue Aug 28 20:04:00 2012 said:
For which final volume? Let us assume you want to have final volume 2 mL for your experiment. You pipette 2 mL = 2000 uL of saline/media whatever.. to which you add X uL of your bacteria at OD600 = 0.4; X being the solution of the below:
2.5*10^9 CFU/mL * X uL of this = (uL final solution+X uL that you add on top) * 10^6 CFU/mL (get rid of the extra zeroes)
2500x = 2000 + x
x = 2000/2499 uL (even though I wouldn't add this little amount < 1 uL) I would do some dilution series before, something like 1 to 100 in order to add 100 times the X volume.
Andreea
For example I need 10 ml
So 2.5*10^9 *** 10000 = ( What is uL final solution+X uL that you add on top) * 10^6 CFU/ml
Please reply...Today I will learn how to check conc
No: 2.5*10^9 *X = ( 10000+X) * 10^6 CFU/ml
ascacioc on Tue Aug 28 20:31:52 2012 said:
No: 2.5*10^9 *X = ( 10000+X) * 10^6 CFU/ml
Thank you
So
2.5 *10^9 *X = (10000+X)*10^6 CFU/ml
2500 X = 10000+X
yup; but again: i wouldn't pipette 4 uL but I would make 1 mL culture at 0.4 diluted to 9 ml media, thorough mix and I would add 40 uL of this to 10 mL.
ascacioc on Tue Aug 28 20:47:04 2012 said:
yup; but again: i wouldn't pipette 4 uL but I would make 1 mL culture at 0.4 diluted to 9 ml media, thorough mix and I would add 40 uL of this to 10 mL.
Thank you. Now I understand. I will practice some more examples, so that I will get good idea on this calculations