How specific are the signals from TF chips?
The spots on TF chips contain two different kinds of double stranded DNA: • the consensus sequence of the specific recognition site (called wild-type) that is highly detected when the corresponding TF is active. These spots are accompanied directly by spots with • mutated sequences that monitor the non specific binding of additional proteins from the nuclear extract. For final calculation of results, each spot is at first corrected against the individual, local background. Afterwards, the signal from the spot with the mutated sequence is subtracted from the signal of the wild-type. With this procedure, the TF chips of Eppendorf offer an extraordinary good quality system that ensures the highest specificity of results about TF activity.
