You perform a serial dilution, using a known concentration of 500 mg/mL in the first tube. Each tube contains 100 μL of dilutant. You withdraw 50 μL from tube 1 and add it to tube 2, and continue with the same dilution protocol for
the subsequent tubes. When you reach tube 11, you discard the 50 μL, leaving 100 μL of dilutant in tube 12.
1-12 tubes