Hi, I receied some CEL files that when I open in a notepad, I see junk. It is in some weird format not readable in ASCII editors. Also the file size is small - 4MB. I saw one my friends converting them to a format readable by ASCII text. When the conversion is done the size increases to over 11 MB. could any one please let me know what could be that software in Windows OS. OR is there any R module that coverts this. Thanks Peri.