Fig. 2

Whole workflow of sperm selection with the device. I Design of device; II device fabrication (detailed information is shown in Fig. 1). III Preparation of forming chemoattractant gradient; IV addition of HTF media into device; V addition of sperm sample after centrifuged with discontinuous density with Percoll to remove seminal plasma (to enable capacitation); VI sperm selection was performed after the sperm swam and were incubated in the device for capacitation at 37 °C for 150 min. After 150 min, sperm at Grooves D2 and E2 were pipetted for the next experiments. HTF, human tubal fluid