Quantity	Material
2	2 ml NH4OH (aq., 5% (vol/vol)) and 0.5 ml air in a 3-ml PP/PE syringe with a 21-gauge × 2-inch needle
2	0.5 ml of 1:1 saline/ethanol in a 1-ml PP/PE syringe without needle
2	2 ml of saline in a 3-ml PP/PE syringe with a 16-gauge × 1½-inch needle
1	Sep-Pak C18 light cartridge
5	1.5-ml number-labeled Eppendorf tubes