TR-FRET（Time-Resolved Fluorescence Resonance Energy Transfer）

• Fluorescence Resonance Energy Transfer (FRET): When a fluorescent molecule (donor) absorbs light energy, it can non-radiatively transfer this excited energy to another molecule (acceptor), provided that the acceptor is in close proximity to the donor (typically within a range of 1-10 nanometers), and there is an overlap between the donor's emission spectrum and the acceptor's excitation spectrum.
• Time-Resolved Fluorescence (TRF): By measuring the decay of fluorescence after the excitation light source has been stopped, it is possible to distinguish between short-lived background fluorescence and long-lived signal fluorescence. TR-FRET typically employs chelates of lanthanide elements (such as europium or terbium) as long-lived donor fluorophores.
• Energy Transfer Process: In TR-FRET, after the donor is excited, if it is in close enough proximity to the acceptor, energy is transferred to the acceptor, causing it to emit fluorescence as well. By detecting the fluorescence after a delay following excitation, it is possible to effectively reduce background interference.

• Simple Operation: No complex washing steps are required, making it easy to automate.
• Wide Linear Range: Capable of detecting both high and low concentrations of samples with a broad linear detection range.
• Rapid Detection: Detection can be completed in as little as 1 hour, significantly improving experimental efficiency.
• Low Background Signal: The long fluorescence lifetime of lanthanide elements allows for delayed detection after excitation, eliminating interference from short-lived fluorescence.

TR-FRET Product Recommendation List

Data Example（abs560012  an example）

* The above data cannot replace the data obtained from experiments and are provided only as examples. Results may vary depending on the TR-FRET compatible instrument used.

Homogeneous Chemiluminescent Assay (HICA)

HICA is a chemiluminescent technology based on nanoparticles. It detects interactions between biomolecules via energy transfer between two types of microspheres (donor and acceptor microspheres). The principle is as follows:

• Donor Microspheres: Coated with a photosensitizer (e.g., phthalocyanine dye). When excited by 680 nm red light, they convert oxygen molecules in the environment into high-energy singlet oxygen.
• Acceptor Microspheres: Coated with a luminescent agent (e.g., a dimethylthiophene derivative) and a rare-earth chelate (e.g., europium). When singlet oxygen diffuses to these microspheres, it excites the luminescent agent to produce fluorescence at around 610 nm.
• Energy Transfer: When the two types of microspheres are brought within 200 nm of each other due to biomolecular interactions (e.g., antigen-antibody binding), singlet oxygen can transfer from the donor to the acceptor microspheres, producing a chemiluminescent signal.

Technical Advantages

• High Sensitivity: Energy transfer from singlet oxygen enables detection limits as low as the femtomolar range.
• Low Background: The detection wavelength is longer than the excitation wavelength, reducing interference from impurities.
• Easy Operation: No washing steps are required, making it suitable for automated and portable detection.
• Miniaturization: Ideal for developing miniaturized, high-throughput detection platforms.

HICA Product Recommendation List

Data Example（abs560034  an example）

Lower Detection Limit: 0.2–3 pg/mL for different matrices Dynamic Range: 0–100,000 pg/mL Linear Range: 0.39–10,000 pg/mL High Concentration CV Value: 1.5–5% Recovery Rate: 90–110% Cross-Interference Rate: 0% for five tested samples

Bioluminescence

• Enzyme-Substrate Binding: Firefly luciferase binds to its substrate luciferin. The enzyme then combines with ATP (adenosine triphosphate) and luciferin to form an enzyme-substrate complex.
• Oxidation Reaction: Catalyzed by luciferase, luciferin reacts with oxygen to form oxyluciferin. During this reaction, chemical energy is converted into light energy, releasing a photon.
• Light Production: The emitted photon produces visible light, typically a yellow-green light with a wavelength of around 560 nm. This light signal can be detected by devices such as luminometers or imaging systems.

Bioluminescence Detection Product Recommendation List

Data Example（abs42075819  an example）

Detection Consumables

Absin provides antibodies, proteins, ELISA kits, cell culture, detection kits, and other research reagents. If you have any product needs, please contact us.

Absin Bioscience Inc. Email: worldwide@absin.cn

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