**Alexa-488-actin filaments**

Prepare 10 μL of a 5 μM solution of 1:1 [*4-A*]:[*A*] to polymerize prior to adding to composite:

6.74 μL PEM-100 0.72 μL 4-A 0.54 μL A 2.00 μL 10 mM ATP

Incubate for 60 min at RT.

Immediately prior to imaging prepare a 1:2 dilution in PEM-100 + 2 mM ATP. Add 1 μL to final sample chamber solution from Section 2.4, replacing the equivalent volume of PEM-100.
