Protein microarrays come in two basic formats, forward and reverse phase. In "forward phase" arrays, captured reagents - whether antibodies, aptamers, or other proteins - are arrayed at defined positions on a glass slide or similar substrate, which is then interrogated with any of a variety of probes, from protein lysate and enzymes to small molecules and nucleic acids.
On the other hand, with a reverse phase array protein lysates are spotted. The arrays are then probed with antibodies, for instance, phosphorylated signaling molecules - one antibody probing multiple samples as opposed to one sample for multiple capture reagents.
All of PolyAn’s reactive surfaces are completely transparent. They are characterized by a low lot-to-lot variation that is specified and monitored by using contact angle measurements as well as qualitative test methods.
More hydrophobic surfaces may result in reduced spot diameter, depending on the spotting buffer composition. Results may vary based on buffers, sample preparation, spotting and scanning instruments.
PolyAn is the distributor of the nitrocellulose film slides from Grace Bio-Labs. The following table illustrates the different product families for RPPA and other microarray applications:
|Binding Capacity ||++++||++||++++||+|
|Dynamic range (log scale fluorescence)||5-6||5-6||7+||4-5|
|Applications||Best for any application requiring high binding capacity and colorimetric detection.||Reduced fluorescence background with lower binding capacity than AVID. Good signal-to-noise ratio for fluorescence detection.||Second generation NOVA, lowest fluorescence background, high binding capacity. Best for fluorescence detection and large dynamic range.||Lowest fluorescence background, lower binding capacity, reduced dynamic range. Best signal-to-noise ratio for fluorescence detection.|