Some assays and procedures require a surface that is nonbinding because many
proteins, enzymes in particular, may become activated or inactivated upon
attachment to a surface. Corning's unique NBS™ treatment (U.S. Patents
6,093,559 and 6,319,664) creates a nonionic hydrophilic surface (polyethylene
oxide [PEO]-like) that minimizes molecular interactions (Figure 1). Since
proteins and other biomolecules passively adsorb to surfaces primarily through
hydrophobic and ionic interactions, the NBS™ surface lacking these
characteristics naturally inhibits nonspecific immobilization via these forces.
Figure 1. PEO chains immobilized on polystyrene create the nonionic
hydrophilic NBS™ surface that minimizes molecular binding.
Results (Table 1) show the NBS™ surface has the ability to significantly
reduce (<2 ng/cm2) protein and nucleic acid binding to microplates,
while maintaining enzyme activity. The nonionic, hydrophilic NBS™ surface
is therefore well suited for enhancement of signal-to-noise in homogeneous
assays such as Scintillation Proximity Assay (SPA). NBS™ surfaces are
stable to aqueous biological fluids and biological reagents containing up to
20% isopropyl alcohol or DMSO or 10 M urea or 1% SDS, and over a pH range
(3-11).
Table 1. Comparison of protein and nucleic acid binding with various polymers
Binding in ng/cm2
125I-IgG
125I-BSA
125I-Insulin
32P-oligoDNA
32P-l phageDNA
Polystyrene (PS)
400
450
310
22
6
Polypropylene 380
380
440
370
3
<2
NBS on PS
<2.5
<2.5
5
<2
<2
Based on a Scintillation Proximity Assay (SPA) using 100 µL/well in 96 well
microplates. Contents were aspirated and washed 3 times with 200 µL/well of
PBS, pH 7.4.
NOTE: Most samples will be shipped upon the request standard UPS ground
service; however some products require additional qualification prior to the
request being fulfilled. For these items a Corning Life Sciences Account
Manager will contact you with additional information.
