Extended Data Fig. 6: Control experiments confirmed the reliability and reversibility of the tension probes.
From: A reversible shearing DNA probe for visualizing mechanically strong receptors in living cells
a, Comparison of DIC images for cells plated on sensors with and without RGD peptide. No cell attachment was found on surface coated with sensors lacking RGD peptide, suggesting that tension signal is specially generated through RGD-integrin interactions. b, Representative DIC images of NIH 3T3 cells seeded on tension probes and fibronectin-coated coverslips at different time points. c, A 45-pN RSDTP that lacks the quencher oligonucleotide was used to further validate the stability and reversibility of tension probes. The images show that the fluorescent background of the surface that lacks the quencher oligonucleotide is three times higher than a surface with the quencher strand DNA. Despite the high fluorescence background of these surfaces, we can still detect a tension signal during cell spreading on these surfaces, because Au NP plays a second quencher here. After treating cells with Cyto D, we found that the tension signals disappeared immediately and didn’t leave any dark features, which are often used to determine the stability of tension probes on the surface18. The fluorescence profiles along the yellow lines in the images are also shown in the right panel.
