- Quantum Leap in Sensitivity
100-Fold and greater increases in sensitivity against fluorescein may be expected when combined with Diatron's Transient-State detection system.
10-Fold (approx) increase in sensitivity against fluorescein may be expected when LaJolla Blue is used with traditional steady- state detection methods.
Sensitivity can be defined by the Signal:Noise ratio. Unwanted noise lowers the signal:noise ratio and thus reduces sensitivity. Three typical contributors to unwanted noise are Background/Auto- Fluorescence, Non-Specific Binding and Raleigh-Raman Scatter.
Members of the LaJolla Blue Family do not bind non-specifically to serum components and cellular elements.
Most background / auto-fluorescence emission is below 700nm. LaJolla Blue emission is normally greater than 705nm, which approaches NIR, so noise contribution from adventitious fluorescence is virtually eliminated.
- Excellent Photostability
The decay of the fluorescent intensity is very slow over time for LaJolla Blue labelled compounds compared to fluorescein.
Fluorographic images of cell labelling done with LaJolla Blue labelled probe (Ab) against Fluorescein labelled probe (Ab) show LaJolla Blue to be several fold more photostable than fluorescein.
This is important for applications requiring extended viewing time, extra-time for image search and focus, re-viewing of previously viewed images, kinetic applications and multiple-frame image capture.
- No Non-Specific Binding
Members of the LaJolla Blue Family do not bind non-specifically to serum components and cellular elements.
Many commercially available fluorophores show good performance in aqueous solutions, but may bind non-specifically to serum components and cellular elements.
- Virtual Elimination of Autofluorescence
Most auto-fluorescence (sometimes known as intrinsic or adventitious fluorescence) emission is below 700 nm. LaJolla Blue emission is normally greater than 700 nm, which approaches NIR, so noise contribution from adventitious fluorescence is virtually eliminated.
Background fluorescence at lower wavelengths, such as the 520nm emission typical for fluorescein, may be very strong.
- No Quenching in Aqueous Buffers
The fluorescence of some other fluorophores is sometimes very high in organic solvents, but may fall dramatically in aqueous solutions.
This is not the case with members of the LaJolla Blue family.
- No Aggregation
Many other fluorophores aggregate in solution which diminishes fluorescence yield and also reduces solubility.
- Easy Labelling & Compounding
Members of the LaJolla Blue family have free carboxyl groups for easy labelling of haptens having a free aliphatic amino group. LaJolla Blue is readily prepared as a variety of activated derivatives including the NHS-ester and imidazolide and free-amino terminated compounds.
LaJolla Blue has been successfully conjugated to oligonucleotides (1, 2), antibodies and streptavidin.
- Technical Specifications (Please note that all values shown are approximate.)
LaJolla Blue is a phthalocyanine with free carboxyl groups and which is caged by two PEG molecules. Intended for Investigational Use Only.
Decay Time: 4.5 nanoseconds (Very important for Fluorescence Polarization assays)
Absorption (Excitation) Max: 680 nm
Fluorescence (Emission) Max: 700 nm
Quantum Yield: 70%
Extinction Coefficient: 170000 L/Mole cm (Twice that of fluorescein)
Structural Formula
