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Posted by Nicolas_D on 28 Jan 2009 at 22:06 GMT

o prove the concept we measured lipid vesicle (∼748*106 Da) adsorption on the sensor interface followed by subsequent binding of the bee venom peptide melittin (2840 Da) to the vesicles. The results show the high dynamic range of the instrument and that measuring the mass and structural changes simultaneously allow a comprehensive discussion of molecular interactions.

The authors only have measured on one array. How can one then "prove the concept" without repeating the experiment on a different array ?

RE: Reproducibility

Brunsli replied to Nicolas_D on 05 Feb 2009 at 13:27 GMT

The experiment shown in the main article shows the reproducibility of several injections (3 lipid injection, 2 melittin injection). Independent measurements (different arrays) are shown in the supplemental material: Mass measurements demonstrating the nature of the cantilever funcionalization. Furthermore, differently designed experiments for combined mode measurements are presented in the supplemental given further insight to the experiments. Also note, that the observed static mode results are in good agreement with data presented previously by an other group (compressive bending upon vesicle injection indicating an expansion of the vesicles*)

*Pera et al. Sensing lipid bilayer formation and expansion with a microfabricated cantilever array. Langmuir : the ACS journal of surfaces and colloids (2007) vol. 23 (3) pp. 1543-7)

RE: RE: Reproducibility

Nicolas_D replied to Brunsli on 12 Feb 2009 at 06:55 GMT

Thanks for the answer.
Looking a the Supplementary information, I indeed have found Fig. S3. for which you mention: "The deflection direction cannot be compared to the results in the manuscript due to the different functionalization.".
I therefore would argue that Reproducibility has not been shown.