The word reductases 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: 15
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (62 words)
actress, assured, austere, casters, catered, causers, cauters, cerates, creased, creases, created, creates, cresset, crested, crudest, crusade, crusted, curated, curates, custard, dearest, decares, decrust, deserts, dessert, ductase, dusters, educate, eructed, euaster, reacted, reasted, recasts, recused, recuses, redacts, redates, reduces, reducts, rescued, rescues, reseats, resects, saucers, sauteed, screeds, seaters, secrets, secured, secures, sedater, sedates, seducer, seduces, sucrase, sudates, tasered, teasers, traduce, tressed, trussed, ureases