Hydrophilic

A range of surfaces to optimize protein binding

Maximize passive adsorption and coating capacity of hydrophilic molecules such as antibodies, proteins, and glycans using these plates manufactured with hydrophilic surfaces including MaxiSorp, MediSorp, and MultiSorp.

Hydrophilic surface types

Slightly hydrophilic:

The slight hydrophilicity of these plate surfaces enhances their ability to bind a diverse range of biomolecules, including glycoproteins, serum-containing samples, and amphoteric molecules such as lipopolysaccharides. With these plates, non-specific adsorption of serum-containing samples is reduced, improving the signal-to-noise (S/N) ratio and consequently, the sensitivity levels.

As the surface is slightly hydrophilic, the maximum binding capacity for a glycoprotein (antibody) will be lower compared to the hydrophilic surface. This will mean that the maximum binding capacity for IgG is less than 650ng/cm2. The immobilization conditions should be calculated from the pI of the molecule that will be coated onto the surface. It is recommended that the pH>pI and a typical coating buffer will often be a carbonate buffer (pH= 9.6) when working with these surfaces.

Hydrophilic:

The hydrophilic surfaces are optimized to bind a high amount of IgG (polyclonal), and these surfaces are ideal for antibody sandwich assays in the enzyme link immuno sorbent assay (ELISA). In addition, they show increased binding of many other proteins and biomolecules that possess hydrophilic/hydrophobic characteristics. The high binding capacity is achieved by a physical modification of the surface.

The maximum binding capacity for IgG is 650ng/cm2. Due to the polarised nature of hydrophilic groups, hybrid hydrophilic and ionic bonds may also be established. Since hydrophilic and ionic groups are often scattered among hydrophobic moieties in macromolecules, a stable adsorption may not be obtained by hydrophilic and ionic bonds alone. A hydrophilic/hydrophobic surface should therefore be chosen, to match hydrophilic/hydrophobic patchwork of the molecule.

Very hydrophilic:

This is the most hydrophilic surface in the portfolio, which many hydrophilic proteins will bind to with a high affinity. The most commonly-used molecules that will bind to these surfaces are glycans. It is also suggested to use this surface for the immobilization of highly polar molecules or for homogenous assays of hydrophobic analytes which will not adhere to the hydrophobic surface.

Binding to the very hydrophilic surface tends to be more pH sensitive. It is important to consider the molecule orientation as this may be controlled to some extent by the buffer composition and pH, so that when large, complex molecules are physically adsorbed, the orientation could be random so that not all the absorbed molecules will be capable of binding the analyte and no signal will be seen.

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