# A biomedical experiment problem

#### yuppy

##### New Member
Dear people,

I am currently doing a biomedical study where there are 4 different treatment. Sham operation, A, B and (A+B). Each treatment have the same 4 time points. (0, 15, 30 & 45) The sample size for each group is 5.

I am doing a proteomics study... i.e each group will give 400+ different proteins which I have to compare them by intensity (Done by computer). However, I need to compare each protein by the treatment (A+B) to the rest with respective to time.

I am sorry, my statistical knowledge is limited to 1 way annova and student t test. Will try SPSS but not very good.

Any suggest how do I tackle this problem?

Thank you!

#### JohnM

##### TS Contributor
You may need to do a repeated-measures ANOVA, since each treatment is measured at 4 successive times, and within each treatment, the time measurements will be related.

#### yuppy

##### New Member

However from my understand of repeated-measures ANOVA, the same samples are taken several times. However within my treatment I have already have a sample size of n=5 in each time point.

Is already a repeated-measures ANOVA? Should I just do repeated-measures ANOVA the whole thing or can I do ANOVA of the regression with respect to time of the treatment?

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#### JohnM

##### TS Contributor
It looks like you may need to do a 2-way ANOVA - 1 between-subjects factor would be the 4 different treatments, and 1 within-subjects factor would be the factor of time.

Here's a link that describes such a study:
http://davidmlane.com/hyperstat/B137541.html