The word radiobiologist is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 21
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (26 words)
astroid, batoids, biodots, bridals, bristol, dialogs, diarist, digital, dilator, disroot, galoots, idolist, libator, libidos, obligor, oilbird, oligist, orbital, ragbolt, tabloid, tabooli, tailors, toolbag, toolbar, toroids, tribals