Our CPN™ products can be conjugated to a variety of molecules for specific targeting.


CPNs™ are readily conjugated to proteins using EDC (N-ethyl-N’-dimethylaminopropyl-carbodiimide) to link amine groups (-NH2) on the protein to the carboxyl groups on the surface of the CPN™ (-COOH). Attachment of proteins such as antibodies or streptavidin will generate highly selective CPNs™ for the detection of target molecules.


The brightness of the CPNs™ ensures the detection of target molecules is highly sensitive, with single molecules being detected in flow cytometry and immunocyto/histochemistry.


The affinity of targeting molecules varies greatly and an initial titration of the CPN™:targeting molecule ratio will need to be undertaken. Similarly, final usage dilution of the CPN™-targeting molecule conjugate will need to be determined empirically.


  1. Add 50 μl CPN™ (0.1mg/ml) to 870 μl of water
  2. Add 20 μl of HEPES 1M
  3. Add 20 μl PEG 5% w/v
  4. Add 40 μl streptavidin (1mg/ml) and vortex (several ratios of CPN™:targeting molecule should be tested to identify the optimum conditions, e.g. 10-100 μl targeting molecule (1mg/ml))
  5. Add 20 μl freshly prepared EDC solution 5 mg/ml
  6. Shake mixture for 4 hours at room temperature
  7. Add 20 μl BSA (10% w/v) and leave to shake for a further 30 minutes
  8. The CPN™:streptavidin conjugates can the be purified from the reaction components by precipitating them using a magnet
  9. Re-suspend in 50 μl PBS


  • HEPES (1M)
  • PEG (5% w/v)
  • Streptavidin (1 mg/ml)
  • EDC [N-(3-Dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride] 5 mg/ml (Freshly make EDC solution and use immediately. Discard any unused.)
  • BSA (10% w/v)
  • Phosphate buffered saline


CPNs™ can be used in a variety of in vitro imaging applications to maximise the success of your R&D.


CPNs™ boast superior optical, biological and structural properties to market equivalents

Why so bright?

Our CPN™ products retain their fluorescence much longer than existing technologies, whilst remaining chemically and thermally stable.
Discover bright