Cytosolic Tracers Product Specification

Biocytin is a very useful cellular tracer that can be introduced into cells by microinjection.

• White solid soluble in water or DMSO.
• Stable at room temperature.
• C₁₆H₂₈N₄O₄S.
• Mwt: 372.48.
• [576-19-2]

Biocytin hydrazide is an aldehyde-fixable cellular tracer that can be introduced into cells by microinjection. Biocytin hydrazide can also be used to label glycoproteins or other carbohydrate molecules

• White solid soluble in DMSO.
• Store at 4°C 
• C₁₆H₃₀N₆O₃S.
• Mwt = 386.51.
• [102743-85-1]

Biotin ethylenediamine, hydrobromide (identical to Neurobiotin) is a useful anterograde and transneuronal tracers. 

• White solid soluble in DMSO.
• Store at -20°C
• C₁₂H₂₃BrN₄O₂S.
• Mwt: 367. 

Biotin ethylenediamine, hydrochloride is similar to biotin ethylenedimine, hydrobromide (90057).

Biotin-4-fluorescein has been reported to be a superior fluorescent biotin derivative for accurate measurement of avidin and streptavidin in crude biofluids. The biotin binding to avidin and streptavidin is high affinity, fast and noncooperative. Also see Fluorescein biotin (80019 ). Please also see biotin-rhodamine 110 (80022 ) for superior photostability.

• l_ex\l_em = 494/523 nm. 
• Yellow solid soluble in DMSO, or pH>7 buffers.
• Store at -20°C and protect from light. 
• C₃₃H₃₂N₄O₈S.
• Mwt. = 644.7 

We developed biotin-rhodamine 110 as an alternative to biotin-4-fluorescein (90062) and fluorescein biotin (80019), both of which have been used for detection of biotin binding sites and the degree of biotinylation of proteins, and for the measurement of avidin and streptavidin in crude biofluids. In addition, biotin-rhodamine 110 can be used as a polar tracer to study the morphology of cells, similar to the use of Lucifer Yellow cadaverine biotin-X ( 80017). The dye rhodamine 110 (or carboxyrhodamine 110) has absorption and emission wavelengths similar to those of fluorescein (See Figures 7.4 and 7.5). However, the spectra and fluorescent quantum yield of rhodamine 110 are relatively unaffected by pH change (pH 4-9), whereas the fluorescence of fluorescein is significantly reduced at acidic pH. Moreover, rhodamine 110 is much more photostable than fluorescein (See Figure 7.6), making biotin-rhodamine 110 a better choice for studies where prolonged exposure to light may be necessary.

• l_ex\l_em(MeOH) = 502/524 nm
• Orange red solid soluble in DMF or DMSO
• Store at -20°C and protect from light, especially in solution
• C₄₁H₅₀N₆O₉S
• Mwt: 802.94

Calcien is a highly negatively charged, water-soluble fluorescein derivative. Its fluorescence is nearly independent of pH in the range between 6.5 and 12. The dye can be introduced into cells by microinjection and is useful for cell tracing and for the study of cell membrane integrity and fusion. Biotium also offers the membrane-permeant version of calcein: calcein AM, which hydrolyzes into calcein once inside cells. 

l_ex\l_em = 494/517 nm (pH 8).

e = 75,000 

Yellow-orange solid soluble in DMSO, DMF or pH>6 water.

Store at -4°C and protect from light.

C₃₀H₂₆N₂O₁₃

Mwt: 623. 

Calcein AM is a widely used green fluorescent cell marker. Calcein AM is membrane-permeant and thus can be introduced into cells via incubation. Once inside the cells, calcein AM is hydrolyzed by endogenous esterase into the highly negatively charged green fluorescent calcein, which is retained in the cytoplasm. Calcein AM is an excellent tool for the studies of cell membrane integrity and for long term cell tracing. Calcein AM is used in our Cell Viability Cytotoxicity Assay Kit (See Bioscience Section for 30002).

• l_ex\l_em--(calcein) = 494/517 nm (Ph 8). 
• Colorless solid soluble in DMSO
• Store at -20°C and protect from light.
• C₄₆H₄₆N₂O₂₃
• Mwt: 995. 

See 80011 for product description.

Calcein AM supplied in a ready-to-use form. See 80011 for more information.

Calcein AM supplied in a ready-to-use form. See 80011 for more information.

The principle of DPA/Tb³⁺ for vesicle fusion assay is based on the fact that contact of the chelator dipicolinic acid (DPA) with terbium (III) forms an instant Tb³⁺-DPA complex that is ~10,000 times more fluorescent than free Tb³⁺. In the assay, separate vesicle populations are loaded with 2.5 mM TbCl3 in 50 mM sodium citrate, or 50 mM DPA in 20 mM NaCl. Fusion of the two types of vesicles results in fluorescence increase at 490 nm or 545 nm, with excitation at 276 nm.^1-4 Each set of product contains 1 g terbium trichloride and 1 g DPA in two separate vials. Please also see SDIP/Europium for membrane fusion assay (#80105), which results in intense red fluorescence upon complex formation.

l_ex\l_em(DPA/Tb³⁺ complex) = 276/490 and 545 nm

Store both reagents at room temperature

A positively charged quencher that is often used with ANTS to study membrane fusion or permeability. See information for ANTS (90010).

Off-white solid soluble in water

Store at -20°C and keep from light, especially when in solution

C₁₈H₁₈Br₂N₂.

Mwt: 422.

[14208-10-7]

Fluorescein biotin can be used to detect and quantify biotin binding sites and the degree of biotinylation of proteins. Also see biotin-rhodamine 110 (80022) and biotin-4-fluorescein (90062) in Section 8.

• l_ex\l_em= 494/518 nm
• Yellow solid soluble in DMSO, or DMF
• Store at -20°C and protect from light
• C₄₂H₅₀N₆O₈S₂
• Mwt: 831
• [134759-22-1]

Hydroxystilbamidine has been used extensively as a retrograde tracer for neurons and also a histochemical stain. Please also see hydroxystilbamidine 4% in H₂O, which is a more convenient, ready-to-use form (80023 ).

• l_ex\l_em= 361/536 nm.
• Yellow solid soluble in water.
• Store at 4°C and protect from light.
• C₁₈H₂₄N₄O₇S₂.
• Mwt: 473.

Hydroxystilbamidine has been used extensively as a retrograde tracer for neurons and also a histochemical stain. The 4% solution in deionized H₂O is a more convenient, ready-to-use form. If desired, the solution can be diluted to a lower concentration. For most of the applications, the typically dye concentration is 2% to 4%.

Like Lucifer Yellow CH (80015 and 80016), Lucifer Yellow Cadaverine can be used as a fixable fluorescent tracer. In addition, the dye can be used to conjugate to carboxylic acid groups. 

• l_ex\l_em=428/536 nm. 
• Yellow solid soluble in water.
• Store at -20°C and protect from light. 
• C₁₇H₁₇K₂N₃O₈S₂.
• Mwt: 534. 

This fluorescent biotin derivative is a very useful tracer for studying neuronal morphology. The biotin portion of the molecule allows researchers to amplify the fluorescent signal using standard biotin-avidin or biotin-streptavidin biochemistry. The staining can tolerate conditions of aldehyde fixation and sectioning, and washing with detergent. 

• l_ex\l_em= 428/532 nm. 
• Yellow solid soluble in water.
• Store at -20°C and protect from light. 
• C₃₃H₄₂K₂N₆O₁₁S₃.
• Mwt: 873. 

Lucifer Yellow CH lithium salt (LY CH lithium salt) is a widely used polar molecular tracer for studying neuronal morphology. The fluorescent molecule contains a carbohydrazide that allow the molecule to be fixable with an aldehyde fixation agent.

• l_ex\l_em=428/536 nm. 
• Yellow solid soluble in water. Store at -20°C and protect from light. 
• C₁₃H₉Li₂N₅O₉S₂.
• Mwt: 457. 
• [67769-47-5]

Lucifer Yellow CH potaasium salt (LY CH potassium salt) is a widely used polar molecular tracer for studying neuronal morphology. The fluorescent molecule contains a carbohydrazide that allow the molecule to be fixable with an aldehyde fixation agent. 

l_ex\l_em=428/536 nm. 

Yellow solid soluble in water.

Store at -20°C and protect from light.

C₁₃H₉K₂N₅O₉S₂

Mwt: 522. 

[71206-95-6]

RuBP-2S is a luminescent ruthenium complex similar to RuBPS (80021). Two of the bathophenanthroline ligands are neutral while the third bathophenanthroline ligand is bis-sulfonated, resulting in an overall neutral charge of the ruthenium complex. RuBP-2S shares the spectral properties of RuBPS and may also have similar applications (See product description for 80021).

• l_ex\l_em(H2O)= 462 (broad)/603 nm
• Yellow solid soluble in water
• Store at 4°C and protect from light
• C₇₂H₄₆N₆O₆RuS₂
• Mwt: 1256.3

RuBP-4S is a luminescent ruthenium complex similar to RuBPS (80021). Two of the bathophenanthroline ligands are bis-sulfonated while the third bathophenanthroline ligand is neutral, resulting in an overall double negative charges of the ruthenium complex. RuBP-4S shares the spectral properties of RuBPS and may also have similar applications (See product description for 80021).

• l_ex\l_em(H2O)= 462 (broad)/603 nm
• Yellow solid soluble in water
• Store at 4°C and protect from light
• C₇₂H₄₄N₆Na₂O₁₂RuS₄
• Mwt: 1460.46

RuBPS is a negatively-charged water-soluble luminescent ruthenium complex. The complex can be efficiently excited by either UV light or visible light in the wavelength range from 400 nm to 500 nm with bright red emission centered around 605 nm . Ruthenium complexes such as RuBPS typically have luminescence lifetimes in the micro second range and a Stokes shift over 100 nm. By using time-resolved luminescence measurement,the combination of long luminescent lifetime and large Stokes shift offer the possibility for extremely sensitive detection that could approach the sensitivity of radioactive detection. Among many potential applications, RuBPS could be used as a polar tracer similar to the uses of Lucifer Yellow and FluoroGold.

• l_ex\l_em(H₂O) = 462 nm (broad)/603 nm.
• Yellow solid soluble in water
• Store at 4°C and protect from light
• C₇₂H₄₂N₆Na₄O₁₈RuS₆.
• Mwt: 1664.55.
• 301206-84-8]

Biotium developed SDIP/Eu³⁺ as an alternative to DPA/ Tb³⁺(80104), which is used for vesicle fusion assays. Similar to DPA/TB ³⁺ assay, one population of vesicles can be loaded with the chelator SDIP while another population of vesicles can be loaded with EuCl₃. Intense red fluorescence is produced when the two types of vesicles fuse as a result of formation of the SDIP/Eu³⁺ complex. The main advantage of SDIP/Eu³⁺ over DPA/TB³⁺ is that the SDIP/Eu³⁺ generates fluorescent emission with brighter intensity and much longer wavelength. Each set of products contain 10 mg SDIP and 25 mg EuCl₃ in two separate vials.

Sulforhodamine 101 has a longer absorption wavelength than does sulforhodamine B. Like sulforhodamine B and G, in addition to their potential use in cancer drug screening, these fluorescent dyes have been primarily used as polar tracers for the studies of neuronal cell morphology and cell-cell communications. See 80100 for more information. 

 

l_ex\l_em = 586/605 nm. 

Red solid soluble in water

Store at room temperature

C₃₁H₃₀N₂O₇S₂

Mwt: 607

[60311-02-6]

Similar to other sulforhodamines, the highly water-soluble sulforhodamine B can also be used as a polar tracer for the studies of cell morphology and neuronal cell-cell communications.^1-3

In addition, sulforhodamine B has been shown to be a superior protein stain for use in the quantification of cellular proteins of cultured cells.⁴ The intensely colored, water soluble dye is particularly useful for in vitro cell-based screening of anticancer drugs.^5,6 The dye is believed to bind to basic amino acids of cellular proteins. Thus, colorimetric measurement of the bound dye provides an estimate of the total protein mass that is related to the cell number. The assay method is simple and reproducible, and the end-point measurement is not time-critical, a significant advantage over assays using tetrazolium derivatives. The method is especially applicable to large scale screenings of anticancer drug candidates from natural extracts or synthetic chemicals.

• l_ex\l_em = 565/586 nm.
• Red solid soluble in water
• Store at room temperature
• C₂₇H₃₀N₂O₇S₂
• Mwt: 559
• [2609-88-3]

Similar to other sulforhodamines, the highly water-soluble sulforhodamine G can also be used as a polar tracer for the studies of cell morphology and neuronal cell-cell communications.^1-3

l_ex\l_em = 529/548 nm. 

Orange red solid soluble in water

Store at room temperature

C₂₅H₂₅N₂NaO₇S₂

Mwt: 553

[5873-16-5]

True Blue is a UV-excitable, retrograde polar tracer that stains cell cytoplasm with blue fluorescence.

• l_ex\l_em= 375/403nm.
• C₂₀H₁₈Cl₂N₄O₂.
• Mwt:417.29.
• [71431-30-6 ]