Does anybody know which is the most efficient method to rinse 50um chitosan microspheres? The microspheres were crosslinked for 45min with 10mM genipin and they are now in ethanol but I need to put them into a citrate phosphate buffer with pH6. I have been centrifuging them, however when I add the buffer and centrifuge again I no longer see the pellet which makes it difficult to continue the washing process. I have been using 7000rpm for 3min. Should I just increase the rpm? Or are there any other methods that I can use?

Thank you all in advance.