Specificity: Specific for the N-terminal portion (aa1-97) of the SF2/ASF protein comprising the RNA-recognition motif (RRM1). Reactivity is not affected by phosphorylation state of SF2/ASF. On Western blots, a band of ~33kD is seen with doublet or triplet bands sometimes evident due to phosphorylation differences. SF2/ASF is highly conserved (e. g. mouse and human protein are 100% identical) so reactivity with other species is likely. Please note, however, that cross-reactivity in non-target species varies and cannot be guaranteed.