Gene Chip Analysis - Filtering of Flagged Data

Filtering of Flagged Data

Filtering of bad intensity spots is an important process of quality control. For example, the scanner has a measurement limit below which intensity values cannot be trusted. Typically, the lowest intensity value of reliable data is 100–200 for Affymetrix data and 100–1000 for cDNA Microarray data. These cut-offs are likely to change as scanners become more precise. Values below the cut-off point are usually removed (filtered) from the data because they are likely to be artifacts.