Isolated allophycocyanin dissociates when in diluted solutions or when it is exposed to chaotropic salts, therefore APC is usually cross-linked such that it is stable for use in biological assay formats. Columbia Biosciences uses a proprietary, non-destructive cross-linking process that increases the thermal stability while maintaining fluorescent and spectral integrity of the native dye.
Structural Characteristics
Allophycocyanin can be isolated from various species of red or blue-green algae, each producing slightly different forms of the molecule. It is composed of two different subunits (α and β) in which each subunit has one phycocyanobilin (PCB) chromophore. The subunit structure for APC has been determined as (αβ)3. The molecular weight of APC is 105,000 Daltons.
| Absorption maximum | 652 nm |
| Additional absorption peak | 625 nm |
| Emission maximum | 657.5 nm |
| Extinction Coefficient (ε) | 2.4 x 105 M-1cm-1 |
| Quantum Yield (QY) | 0.68 |
| Brightness (ε x QY) | 1.6 x 105 M-1cm-1 |
| A650/A280 ≥ 4.5 |
| A650/A620 ≥ 1.25 |
| Cross-link Ratio ≥ 1.0 |
| Cross-link ratio is a measure of A650/A620 by diluting 0.1 mg SureLight® APC into 1 ml 50 mM Tris-HCl, 1 M sodium perchlorate, pH 7.0 |
Size |
Price |
|---|---|
≥ 5mg |
$50/mg |