Background Correction Method

Select a method for background correction. As availability of specific methods varies by process, you might see different combinations of the following choices.

The methods are summarized as follows:

Method	Description
None	Applies no background correction.
Kernel Surface	Subtracts a smooth background surface computed by averaging over blocks of data. Shifted Log 2 transformation is recommended when applying the Kernel Surface method. Adding a constant ( 16 to 32 ) as a Shifting Factor will help stabilize the variation at the low expression range after log transformation.
MM	Uses the mismatch values as background to be subtracted from perfect match values. Note : This method cannot be applied for WT-Gene and Exon arrays.
RMA	Applies RMA (Robust Multi-array Average) background correction.
GCRMA	Applies GCRMA (Gene Chip Robust Multi-array Average) background correction. Note : This method requires the corresponding tab-formatted probe sequence file.

To Choose a Background Correction Method:

Click the radio button corresponding to the desired method.