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Reproducibility - (Jan/18/2007 )

Hi Guys

Last week I did a time response experiment to study the effect of a growth factor on erk pathway. I treated the cells for 5, 10, 15, 30, 60 minutes and lysed them n them ran western n probed for phospho erk 1/2. i ontained a very nice time response for a duplicate experiment ( two times done at the same time). I picked the point (15 minutes) at which maximum activation occured and wanted to study the effect of drugs on this activation however i coud not obtain the activation again ( I could nto see the response i saw last week). I dont know why ??????????????????????????????

Ill appreciate any help,,,,,,, thanks

-OUSSU79-

QUOTE (OUSSU79 @ Jan 18 2007, 07:43 PM)
Hi Guys

Last week I did a time response experiment to study the effect of a growth factor on erk pathway. I treated the cells for 5, 10, 15, 30, 60 minutes and lysed them n them ran western n probed for phospho erk 1/2. i ontained a very nice time response for a duplicate experiment ( two times done at the same time). I picked the point (15 minutes) at which maximum activation occured and wanted to study the effect of drugs on this activation however i coud not obtain the activation again ( I could nto see the response i saw last week). I dont know why ??????????????????????????????

Ill appreciate any help,,,,,,, thanks


I recapitulate to check if I´m right: you did ERK phosphorylation kinetics with peak maximum phosphorylation after 15 min of induction; then you did kinetics after drug treatment but ERK was not phosphorylated;

or you did the same experiment two times with totally different results?? (if the last assumption is right, try a third and fourth time)

to give clues it might be useful to tell us more about the drug or, at least, kind of drug

-The Bearer-

I did the first experiment that showed maximum activation of erk after 15 min treatment. IT was in duplicate and I got the same exact results for both of them. when i tried the same exact experiment the 3rd time., I did not get any erk phosphorylation.. I dont know why till now, is it something wrong with the cells or the growth factor i'm using ??????



QUOTE (The Bearer @ Jan 19 2007, 05:05 PM)
QUOTE (OUSSU79 @ Jan 18 2007, 07:43 PM)
Hi Guys

Last week I did a time response experiment to study the effect of a growth factor on erk pathway. I treated the cells for 5, 10, 15, 30, 60 minutes and lysed them n them ran western n probed for phospho erk 1/2. i ontained a very nice time response for a duplicate experiment ( two times done at the same time). I picked the point (15 minutes) at which maximum activation occured and wanted to study the effect of drugs on this activation however i coud not obtain the activation again ( I could nto see the response i saw last week). I dont know why ??????????????????????????????

Ill appreciate any help,,,,,,, thanks


I recapitulate to check if I´m right: you did ERK phosphorylation kinetics with peak maximum phosphorylation after 15 min of induction; then you did kinetics after drug treatment but ERK was not phosphorylated;

or you did the same experiment two times with totally different results?? (if the last assumption is right, try a third and fourth time)

to give clues it might be useful to tell us more about the drug or, at least, kind of drug

-OUSSU79-

are you sure that your kinase is still active? it may have denatured in the time between assays.

-mdfenko-

QUOTE (OUSSU79 @ Jan 22 2007, 07:57 PM)
I did the first experiment that showed maximum activation of erk after 15 min treatment. IT was in duplicate and I got the same exact results for both of them. when i tried the same exact experiment the 3rd time., I did not get any erk phosphorylation.. I dont know why till now, is it something wrong with the cells or the growth factor i'm using ??????



QUOTE (The Bearer @ Jan 19 2007, 05:05 PM)
QUOTE (OUSSU79 @ Jan 18 2007, 07:43 PM)
Hi Guys

Last week I did a time response experiment to study the effect of a growth factor on erk pathway. I treated the cells for 5, 10, 15, 30, 60 minutes and lysed them n them ran western n probed for phospho erk 1/2. i ontained a very nice time response for a duplicate experiment ( two times done at the same time). I picked the point (15 minutes) at which maximum activation occured and wanted to study the effect of drugs on this activation however i coud not obtain the activation again ( I could nto see the response i saw last week). I dont know why ??????????????????????????????

Ill appreciate any help,,,,,,, thanks


I recapitulate to check if I´m right: you did ERK phosphorylation kinetics with peak maximum phosphorylation after 15 min of induction; then you did kinetics after drug treatment but ERK was not phosphorylated;

or you did the same experiment two times with totally different results?? (if the last assumption is right, try a third and fourth time)

to give clues it might be useful to tell us more about the drug or, at least, kind of drug



if your experiment subsequently two-times succeed there is some likeliness that your third experiment failed by any reason; so, better try a fourth time and see what will happen; that kinases do adaptation kinectics is normal and do no kinetics may only explained by absence, total inhibition or denaturization;

-The Bearer-