Except that the katakana word 「セルフ」 doesn't seem to be listed as a prefix in dictionaries; it is listed as a noun. There are a very small handful of katakana words which begin with セルフ though, such as セルフサービス like mogmog pointed out, or セルフイメージ, but I don't think this makes セルフ a prefix.
自【じ】is a prefix meaning 'self-' however...
July 13, 2014 at 12:15am