TABLE 1.
Molecular weights of PEG0 and the m-PEGs
| Surface of particle | Molecular weight of surface group (g/mol) | 〈Fadmax〉 (nN) |
|---|---|---|
| PEG0 | 73 | 0.27 ± 0.01 |
| PEG6 | 330 | 0.35 ± 0.02 |
| PEG43 | 1900 | 0.69 ± 0.04 |
| PEG113 | 5000 | 0.26 ± 0.01 |
| MixPEG | 330 and 5000 | 0.48 ± 0.05 |
The analyzed data is from the frequency versus Fadmax histograms of a pure PEG0 modified silica particle, a pure PEG6 modified silica particle, a pure PEG43 modified silica particle, a pure PEG113 modified silica particle, and a silica particle modified with a mixed monolayer of 65% PEG6 and 35% PEG113 (MixPEG). One-hundred force curves were measured using 100 different living B16F10 cells for each probe type. Here, 〈Fadmax〉 indicates the center of the Fadmax peak, obtained by fitting the histogram with a Lorentzian curve.