Board Thread:News and Announcements/@comment-5973594-20140327162501/@comment-93957-20140329040914

0:42 - Sachs (Shredder) mentions that he and April's father are behind the mutagen, or at least he alludes to it. Shredder was directly involved with the Turtles' mutation in the 1987 cartoon (poured it into the sewer in an attempt to kill Hamato Yoshi) and indirectly in the 2003 series (caused the Utroms to crash to earth, where the mutagen became a byproduct of their Transmat machines). April's father works at Stock Gen in the IDW comic and has been alluded to have had some sort of developmental background with the ooze.

1:14 - April faints when Michelangelo takes off his mask. April fainting when she first meets the Turtles isn't in every incarnation, but it happens so consistently that this is quite obviously a nod to that.