Author: William Hancock
Q: What concentration of tubulin is needed to create a full monolayer of tubulin on the surface of a flow cell?
A: Tubulin is 8 nm x 4 nm = 32 nm2. Therefore, in a 1 um2 area on the surface (106 nm2), roughly 30,000 tubulin can bind. If the flow cell is 200 um deep, and so there is a 100 um deep layer of solution above each of the two glass surfaces, then the volume for each um2 of area on each glass surface is 100 um3. Therefore, if all tubulin stick to the surface, a concentration of 300 tubulin/um3 is needed. Using the rule that 1 nM concentration is equivalent to 0.6 particle/um3, or 1 particle in a 1 um3 volume is 1.6 nM concentration, this comes out to:
500 nM or 0.5 uM concentration of tubulin to generate monolayer in a flow cell.
Q: If we have 1 nM gold nanoparticles in a flow cell and they all stick to the flow cell surface, what particle density do we expect on the surface?
A: For a 200 um thick flow cell with two glass surfaces, the particles for every 1 um2 area on the surface corresponds to a volume of 100 um3. Using the rule that 1 nM concentration is 0.6 particle/um3, this comes out to 60 particles. Therefore:
60 particles/um2 for a 1 nM concentration of gold in the flow cell.
