Sentence:  Five milliamperes / <WSD>cell</WSD> were applied for 18 hr , after which the strips were stained with bromophenol blue and densitometry was carried out using a Spinco Analytrol . 
Meaning of the word marked with <WSD> tags:  (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals