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maria traka IFR
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30
@maria-traka-ifr-5544
Last seen 10.3 years ago
Dear list,
I am not sure how to create the proper design in limma for my
experiment which I think is a factorial and paired combined.
I have 9 patients that are on 3 different diets (3 patients each) and
I have paired samples (pre and post) for each. So I have a total of 18
Affy arrays.
I want to mainly determine the genes that are affected in each diet.
Then I also want to get the genes that are changing in the diets at
the 'pre' stage to get an indication of the variation in my starting
population. So I have made a targets file that looks like this:
targets
ArrayNames Person Diet Time
1 JALI-173_post 173 Control post
2 JALI-173_pre 173 Control pre
3 JALI-205_post 205 lowFV post
4 JALI-205_pre 205 lowFV pre
5 JALI-223_post 223 Control post
6 JALI-223_pre 223 Control pre
7 JALI-225_post 225 highFV post
8 JALI-225_pre 225 highFV pre
9 JALI-235_post 235 lowFV post
10 JALI-235_pre 235 lowFV pre
11 JALI-245_post 245 lowFV post
12 JALI-245_pre 245 lowFV pre
13 JALI-252_post 252 highFV post
14 JALI-252_pre 252 highFV pre
15 JALI-263_post 263 highFV post
16 JALI-263_pre 263 highFV pre
17 JALI-276_post 276 Control post
18 JALI-276_pre 276 Control pre
then,
person<-factor(targets$Person)
diet<-factor(targets$Diet, levels=c("highFV","lowFV","Control"))
time<-factor(targets$Time, levels=c("Pre", "Post"))
So I am kind of stuck with the design and the model to use for my data
and also how to make contrasts and get the comparisons I want.
Please can you give me any help?
Thanks in advance.
Maria
Maria Traka, PhD, MSc
Food & Health Programme Science Manager,
Institute of Food Research, NR4 7UA, UK
Tel: +44 (0) 1603 255194 Fax: +44 (0) 1603 507723
e-mail: maria.traka@ifr.ac.uk<mailto:maria.traka@bbsrc.ac.uk>
www.ifr.ac.uk www.foodandhealthnetwork.com
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