Sentence:  The <WSD>precipitate</WSD> was washed twice with an 80 % saturated solution of * * f , dissolved in a small quantity of 0.1 M neutral phosphate buffer , dialyzed against cold distilled water till free from ammonium ions , and lyophilized using liquid nitrogen . 
Meaning of the word marked with <WSD> tags:  a precipitated solid substance in suspension or after settling or filtering