I'm a senior biology and physics major, and I'm working on a research project to measure cell membrane tension in MCF-7 cells using the optical tweezers. My current strategy has been to use 1um carboxylated beads which would stick to the membrane well. I then use the optical tweezers to trap the bead and move it a specific distance while I record it on camera. I then use RapidStorm to create a heat map of the bead's position, and determine if the bead left the trap during movement, and how far it left the trap. I can theoretically then determine the membrane tension by finding the dx of the bead from the trap and applying it to my calibration curve to find the force.

Sorry for the kind of long description, but I wanted to provide context. I'm having trouble actually trapping a bead that is stuck on the membrane. I can trap beads that aren't on the membrane, but as soon as I go to try and trap the bead on the membrane, it still has a lot of movement (too much for it to be trapped). Is there anything you guys can think of that I might be doing wrong? Or are there any improvements to my experimental that might affect the outcome? Thanks in advance!