 dual cation activ bovin len autolysi autolyt activ bovin len extract 55 ph 7 4 markedli influenc simultan presenc mono- dival cation cation test 2 5 5 mm 5 10 mm produc best activ stimul synergist basi laboratori suggest combin cation requir activ neutral proteinas len presenc averag physiolog lenticular level autolysi suppress basal level obtain presenc 