Dear BioC, I have downloded and installed BioC 1.7 version of yeast2, yeast2cdf, yeast2probe. When I do QCReport(affybatch)...it gives me error: Computing expression calls... ............done. scaling to a TGT of 100 ... Scale factor for: DS1 0.0423884692508222 Scale factor for: DS2 0.0499666090393549 Scale factor for: DS3 0.0505241951060618 Scale factor for: DS4 0.044329057863556 Scale factor for: DS5 0.0540682217606064 Scale factor for: DS6 0.0492654248049955 Scale factor for: DS7 0.0443520296412118 Scale factor for: DS8 0.0593600644059379 Scale factor for: DS9 0.0487530841924384 Scale factor for: DS10 0.0433136489850759 Scale factor for: DS11 0.0383411796140063 Scale factor for: DS12 0.0381174688056688 Error in qc.affy(unnormalised, ...) : I'm sorry, I do not know about chip type: yeast2cdf Execution halted Any help will be great, Thank you in advance, Saurin