From the Airport:
Take the S-Bahn, lines S8 or S9
direction "Hanau" (platform Regio 1),
get off at "Hauptbahnhof" (central station)
then go on as described below:
From Central Station:
Take underground line U4 direction "Bockenheimer Warte" and get off at the final station "Bockenheimer Warte".
Take the exit "Senckenbergmuseum".