User:Igor R. Kuznetsov/Notebook/RBL-2H3/2010/02/22

RBL-2H3

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Hover test I assembled a chamber with cells that were allowed to settle for 60 minutes under room temperature in growth media on clean glass. After 60 minutes, I added equal amount of hepes to the sample to increase the light transmission. I also added BSA beads. The cells appear settled and attached, but not spreading significantly. There were no lamellae that I could detect. An attempt to bring a 1 μm bead over the top of the cell failed (I estimated the hight of the dorsal membrane to be about 5-7 μm based on defocusing). It feels like the body of the cell interferes with a 50 mW trap enough to knock out a 1 μm bead. If I pick up a 2 μm bead with the same trap power, I am able to lift it high enough and bring it over the cell surface, although the cell does interfere with the bead image making it somewhat asymmetric. Image: a bead above (left), and touching (right) the dorsal surface. Conclusion: we do need broad lamellae. Otherwise the interference with both the trap and the bead image is too great.