to determine what constituent of the buffer was responsible , ejaculated semen was diluted 1:10 at 37 degrees c with the following 20 % egg yolk ( vol/vol ) -containing buffers : tes-tris , tes-tetramethylammonium hydroxide , taurine-tris , citric acid-tris , citrate , egg yolk salts , egg yolk proteins tris , and citrate-taurine .
C0055819
citric acid
C0008857
citrate