2-(naphthalen-1-yl)-5-phenyloxazole

2-(Naphthalen-1-yl)-5-phenyloxazole (α-NPO) is an organic fluorescent dye featuring a nitrogen atom, potentially interacting with nitrogen introduced during the amination step [1].

bis-ANS is a high-affinity non-covalent extrinsic fluorescent dye used to analyze protein conformation.[1] Its predominant interaction with proteins is through its hydrophobic phenyl and naphthyl rings.[2] bis-ANS has an excitation maxima of 390 nm.[3] It has an emission maximum of 523 nm when free in solution but undergoes a blue shift with an increase in fluorescence intensity when bound to protein; for example, when bound to intestinal fatty acid binding protein (FAPB2) it has emission maxima of 484-496 nm. bis-ANS has been used to label mechanically damaged neurons in acute brain slices.4 It also potently inhibits microtubule assembly.[5],[6]

The rapid, selective, and sensitive sensing of thiols is important in diverse areas of research. This thiofluor 623 responds upon exposure to thiols with an increase in fluorescence intensity of up to 120-fold. The response is selective for thiols and occurs in aqueous media. In the absence of thiols, the probe is essentially non-fluorescent; thiols cause cleavage of the probe, generating a fluorophore with an absorption maximum of 563 nm and emission at 623 nm. The fluorescence quantum yield of the cleaved product, generated in response to thiols, increases in more viscous media, suggesting ideal performance in biological systems and applicability to single-molecule or 2-photon sensing schemes. The thiofluor 623 is cell-permeable and reacts selectively with intracellular thiols. The pseudo-first order rate constant (kobs) depends on substrate (e.g., 2.1 x 10-3 s-1 for cysteine, 2.0 x 10-5 s-1 for human serum albumin).

5(6)-Carboxy-2',7'-dichlorofluorescein diacetate is an oxidant-sensitive and cell-permeable fluorescent probe.1Base hydrolysis of the ester bonds by intracellular esterases releases the acetate groups and the resulting compound, 5(6)-carboxy-2',7',-dichlorofluorescein, is oxidized by reactive oxygen species (ROS) and nitric oxide (NO) and displays excitation emission maxima of 504 and 530 nm, respectively, which can be quantified as a measure of oxidant production. 1.Hempel, S.L., Buettner, G.R., O'Malley, Y.Q., et al.Dihydrofluorescein diacetate is superior for detecting intracellular oxidants: Comparison with 2',7'-dichlorodihydrofluorescein diacetate, 5(and 6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate, and dihydrorhodamine 123Free Radic. Biol. Med.27(1-2)146-159(1999)

Biotin-11-dUTP [tetra(triethylammonium) salt] [(2S,3S,4R,5R,6R)-5-(2,4-dioxopyrimidin-1-yl)-4-hydroxy-6-(hydroxymethyl)-2-[(3aR,4S,6R,6aS)-2-oxohexahydro-2H-thieno[3,4-d]imidazol-4-yl]-tetrahydro-2H-furo[3,2-d][1,3,2]dioxaphosphorin-3-yl]phosphonate] is used as a fluorescent substitute for dTTP.

Flutax-2 (5 6-mixture), an active fluorescent derivative of paclitaxel, binds to polymerized α,β tubulin dimers, with an excitation emission wavelength of 496 524 nm. Derived from paclitaxel, a diterpenoid secondary metabolite from Taxus species utilized in various cancer research [1], it requires storage protection from light.

Biotin-16-deoxyuridine-5'-triphosphate (Biotin-16-dUTP) trisodium serves as an enzymatically incorporable substitute for its natural analog, dTTP, in DNA cDNA synthesis, facilitating the production of biotinylated DNA probes for diverse assay applications [1] [2]. Storage recommendation: protect from light.

5-Dodecanoylaminofluorescein, a lipophilic fluorescent probe conjugated with a free fatty acid derived from fluorescein, is used to analyze membrane fluidity and assess the critical micelle concentration of detergents. Additionally, it serves as a precursor in the synthesis of hydrophobic nanospheres suitable for drug delivery [1] [2] [3].

Compound 5, 2,3-Di(furan-2-yl)quinoxaline, is a blue-fluorescent quinoxaline derivative that is cell-permeable and demonstrates sufficient brightness at a micromolar concentration of 1.5 μM [1].

1,2-Diaminoanthraquinone serves as a sensitive, specific, and nontoxic fluorescent probe for nitric oxide (NO), facilitating the detection of NO production in live cells and animals. It exhibits maximal absorption at approximately 540 nm and achieves a detection limit of 5 μM for NO [1] [2].

FFN246, a fluorescent probe, concurrently targets the serotonin transporter (SERT) and vesicular monoamine transporter 2 (VMAT2), exhibiting excitation and emission spectra at 392 427 nm, respectively. It serves to label serotonergic neurons within mouse brain tissue via SERT-dependent accumulation [1].

Z-Gly-Pro-Arg-4MβNA is a thrombin substrate that, when cleaved by thrombin, releases 4-methoxy-2-naphthylamine (4MβNA). The liberated 4MβNA reacts with 5-nitrosalicylaldehyde, forming an insoluble yellow fluorescent product, which indicates the site of thrombin activity [1].

Fmoc-Lys(5-FITC)-OH serves as a fluorescent marker for polypeptides and proteins, utilizing FITC—a pH and Cu^2+-sensitive dye—as its fluorescence probe for amine labeling [1] [2] [3].

1,N6-Ethenoadenosine 5'-monophosphate sodium (1,N6-Etheno-AMP sodium), a fluorescent analog of adenosine 5'-monophosphate (AMP), serves as an effective probe for AMP-related systems due to its detectability at low concentrations. It is characterized by an excitation wavelength range of 250-300 nm and emits at 415 nm [1] [2].

2'-Deoxy-1,N6-ethenoadenosine-5'-O-triphosphate (ε-dATP), a fluorescent derivative of 2'-deoxyadenosine-5'-O-triphosphate (dATP), promotes sister chromatid exchange in stimulated primary mouse spleen T- and B lymphocytes with LPS or concanavalin A at concentrations of 50 to 150 µM. Utilized in ambiguous base pairing investigations within vinyl chloride-induced mutagenesis research, ε-dATP, along with its related compound ε-ATP—which exhibits an emission peak at 415 nm after being excited at 300 nm—contributes to understanding genetic alterations mechanisms.

2'(3')-O-Anthraniloylguanosine-5'-O-triphosphate (2'-ANT-GTP) and 3'-ANT-GTP are fluorescent derivatives of GTP that exhibit spontaneous isomerization. 2'(3')-ANT-GTP features an emission peak at 428 nm when excited at 330 nm in aqueous conditions. It functions as an inhibitor of several adenylyl cyclases, notably mammalian adenylyl cyclase 1 (AC1; Ki = 10 nM with manganese), inhibits B. anthracis adenylyl cyclase toxin edema factor (Kis = 4.1 and 13 µM with manganese and magnesium, respectively), and B. pertussis adenylyl cyclase toxin CyaA (Ki = 29 µM with manganese).

10-(4-(Bis(2-hydroxyethyl)amino)phenyl)-5,5-difluoro-1,3,7,9-tetramethyl-5H-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborinin-4-ium-5-uide, a derivative of BODIPY, serves as a fluorescent indicator specifically for the detection of Pb 2+ with an excitation at 504 nM and emission at 510 nM [1] [2].

2-4-(2-Cyanoethyl)(2-phenylethyl)aminophenylazo-5-nitrobenzonitrile is characterized by its storage stability and its fluid, nonagglomerating dispersion properties as an azo dye [1].

5(6)-Carboxy-2',7'-dichlorofluorescein diacetate N-succinimidyl ester (cDCFDASE) serves as a fluorescent probe for assessing the intracellular pH (pH in) in living cells under various external pH conditions (pH ex) [1]. This compound is utilized to measure pH dynamics within cells, facilitating critical insights into cellular function and behavior.

5(6)-Carboxy-2',7'-dichlorofluorescein serves as an excellent substrate for the MRP2 vesicular transport assay, offering superior detection and transport characteristics [1].

5(6)-SFX, SE (Compound SFX-SE) is a fluorescent dye used for labeling primary amines and nascent proteins [1] [2].

5-Br-PAPS, a highly specific Zn 2+ metallochromic indicator, is utilized in assays to measure free Zn 2+ by forming a deeply colored red Zn 2+ complex [1].

5-Nitro BAPTA, a calcium chelator, combined with 2-Me-substituted TM (as a fluorescent moiety), forms a red fluorescent probe (CaTM-2 AM) for imaging cytoplasmic Ca 2+ in cultured living cells. It serves as a building block for synthesizing Ca 2+ specific chelators, Ca 2+ buffers, and fluorescent Ca 2+ indicators [1] [2].

5-Nitro BAPTA tetramethyl ester, a calcium chelator, is involved in the synthesis of two-photon probes and is used for real-time imaging of intracellular calcium ions and monitoring calcium waves at depths of 100-300 μm in liver tissues for 1100-4000 s. Additionally, in conjunction with fluorescent compound 2-Me-substituted TM, it can form a red fluorescent probe (CaTM-2 AM) [1] [2].