PureSperm 40/80/90PureSperm 40 80 90 Gradient Ready diluted to save gradient preparation time. All the advantages of a PureSperm 100 gradient, plus ready diluted to save preparation time. PureSperm 40, PureSperm 80 in both 100mL & 20mL and PureSperm 90 in 100mL, are formulated to minimize sudden pH and osmolarity changes during the transition of sperm from the semen sample to the fertilization medium. This helps to avoid premature hyperactivation and improves