Th e precipitate was centrifuged for 20 min at 12,000 rpm in a micro centrifuge. Ethanol solution was discarded by decantation and pellet was washed with 1 mL of 70% ethanol.
Th e precipitate was centrifuged for 20 min at12,000 rpm in a micro centrifuge. Ethanol solutionwas discarded by decantation and pellet was washedwith 1 mL of 70% ethanol.