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.
Spectral Characteristics
| 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 |
Specifications
| 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 |
