Effect of physicochemical anomalies of soda-lime silicate slides on biomolecule immobilization.
Glass microscope slides are considered by many as the substrate of choice for microarray manufacturing due to their amenability to various surface chemistry modifications. The use of silanes to attach various functional groups onto glass slides has provided a versatile tool for the covalent immobilization of many diverse biomolecules of interest. We recently noted a dramatic reduction in biomolecule immobilization efficiency on standard microscope slides prepared using a well-characterized silanization method. A survey of commercial soda-lime slides yielded the surprising result that slides purchased prior to 2008 had superior immobilization efficiencies when compared to those purchased after 2008. Characterization of the slides by X-ray photoelectron spectroscopy (XPS), contact angle measurements, and atomic force microscopy (AFM), revealed a significant correlation (R > 0.9) between magnesium content, surface roughness, and bioimmobilization efficiency. High performance slides had higher magnesium content and higher root-mean-square (rms) roughness (P < 0.005) than slides with lower bioimmobilization efficiencies. Although the exact mechanism of how magnesium content and surface roughness affect silane deposition has not yet been defined, we show that recent changes in the chemical and physical properties of commercial soda-lime slides affect the ability of these slides to be covalently modified.
North
Stella H
SH
Center for Bio/Molecular Science & Engineering, U.S. Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, D.C. 20375, USA.
Lock
Evgeniya H
EH
King
Tiffany R
TR
Franek
James B
JB
Walton
Scott G
SG
Taitt
Chris R
CR
D017610:Calcium Compounds / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D017640:Silicates / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry*; D013499:Surface Properties
D017610:Calcium Compounds; D010087:Oxides; D017640:Silicates; C004569:soda lime; D012972:Sodium Hydroxide