Curve convertor

ICA stands for “Independent Component Analysis”, a technique that compares signals to each other and explores dependencies, i.e. common trends in the signals. It subtracts the common parts so that only independent signal is left. The idea is to subtract signal resulting from spectral overlap. In case of chromatogram profiles from automated sequencers, there is always some spectral overlap between the different dyes. This is usually compensated by applying a color correction matrix (Applied Biosystems), after which no further correction is needed. However, other sequencers (Beckman and/or Amersham) do not provide chromatogram files for which the spectral overlap is corrected and therefore we decided to implement our own matrix in CrvConv. You can either enter the correction factors manually or have the program find them automatically by using ICA. The best way to use this feature is to create the correction matrix based upon real sequence traces, because here one knows there should never be “natural” overlap between peaks: every overlap is caused by signal bleed through.