Whole array data normalization, when used, was performed independently for each slide by dividing each spot's intensity (after background subtraction) by the median signal intensity of all test probes.

Unfortunately, the solar weather and other changes mean that it fluctuates so much that this sort of background subtraction has been impossible.

Before carrying out the analysis, the data must be pre-processed by background subtraction, computation of ratios and array-wise normalization.

For more information on background subtraction, please review the Salk cDNA analysis algorithm guide in the user's manual folder, available with the online version of this article or at [ 23].

After background subtraction, the cDNA array signals are linearly scaled and normalized to compensate for non-biological variation (for example, differential fluorophore incorporation, different amounts of labeled sample, array-to-array variability).

Mismatches are meant to detect cross hybridization components of their corresponding matches, and are used by MAS4 for probe-specific background subtraction.

If, after background subtraction, one RNA (b i ) is undetectable while a i yields a measurable signal, then a i / b i approaches infinity.

They're using background subtraction to put you in the movie, and it's not very robust, that's why we haven't done it in any of our games.

Ratio image analysis Image processing was in three principal steps: background subtraction, correction for spectral overlap and ratio generation.

Since the actual absorbance value is taken at many data points at equal intervals, background subtraction is generally unnecessary.