Volume = Amount / Desired Concentration
Resuspension is dissolving or dispersing a pelleted or precipitated substance (cells, proteins, DNA, chemicals) in a buffer to a known concentration. After centrifugation, the supernatant is removed and buffer is added to the pellet. Volume = amount/concentration. For cell pellets, resuspension volume determines cell density. For proteins: resuspend gently (vortexing can denature); use appropriate buffer (pH, ionic strength, protease inhibitors). For DNA pellets (ethanol precipitation): air-dry, then resuspend in TE buffer or nuclease-free water at desired ng/μL. Tips: use a small volume first, mix well, then add remaining volume to reach target. Under-resuspension leads to loss; over-resuspension gives dilute samples.