Use the dilution equation: Ci * Vi = Cf * Vf

initial and final states, where "f" is final and "i" is initial.

Solve for Vf (final volume):

Say initial concentration: Ci = X

Say final concentration: Cf = (1 / 100) * X = X / 100

Vf = (Ci / Cf) * Vi

= [X / (X / 100)] * 200 µL

= 100 * 200µL

= 20,000 uL

= 20 mL

Take 200µL of chloroplast solution at some "X" concentration and add 19.8 mL of isolation buffer to make a (1 / 100) dilution. You have 20 mL worth of this dilute solution. That is enough.