I dealt with some Affymetrix data , a part of which is pasted below
ID_REF |
VALUE |
ABS_CALL |
DETECTION P-VALUE |
10071_s_at |
3473.6 |
P |
0.000219 |
1053_at |
643.2 |
P |
0.000673 |
117_at |
564 |
P |
0.000322 |
1255_g_at |
9.4 |
A |
0.602006 |
1294_at |
845.6 |
P |
0.000468 |
1320_at |
94.3 |
A |
0.204022 |
1405_i_at |
6546.2 |
M |
0.0631 |
14312_at |
54.1 |
P |
0.003067 |
1438_at |
461.3 |
P |
0.000562 |
Where i easily can decide the calls either Present, Absent or Marginal.
I have some illumina bead array data also, shown below
ID ILMN_1681101 |
Pvalue Intenstiy 0.27403 |
6.966361247 |
ILMN_2094942 |
0.18961 |
7.00337736 |
ILMN_1703142 |
0 |
7.600470477 |
ILMN_2271336 |
0.37662 |
6.935459748 |
ILMN_2337789 |
0.08312 |
7.064877464 |
ILMN_1669592 |
0.00519 |
7.24596858 |
ILMN_1735038 |
0.05325 |
7.089582893 |
Can i use pvalue here to make Present, Absent or Marginal call same as Affymetrix data. Thanks
Additionaly if you have preprocessed your data with limma,
you can use
expressed_probes <- rowSums(norm.data$other$Detection < 0.01) >=N # N=Number of samples you want to be present and norm.data your normalized set class:"EList"
filtered <- norm.data[expressed,]
Dear Svlachavas, thanks for your comments.