目錄:上海索寶生物科技有限公司>>分子生物學試劑>>核酸生物素標記及檢測試劑盒>> C-34777cholera toxin subunit B (recombinant)
Brand: | ALEXA FLUOR® |
Product Size: | 100 µg |
Protein Subtype: | Cholera Toxin |
Absorption and fluorescence emission spectra of Alexa Fluor® 594 goat anti–mouse IgG antibody in pH 7.2 buffer.
Revised: 02?September?2003
Product Information
Cholera Toxin Subunit B (CT-B) Conjugates
Storage upon receipt:
? ≤ ?20°C
? Desiccate
? Protect from light
Abs/Em: See Table 1
Introduction
Table 1. Conjugates of cholera toxin subunit B.
Unit Size Label Abs/Em *
100 µg 500 µg
Alexa Fluor 488 495/519 C-34775 C-22841
Alexa Fluor 555 555/565 C-34776 C-22843
Alexa Fluor 594 590/617 C-34777 C-22842
Alexa Fluor 647 650/668 C-34778
Biotin NA C-34779
Horseradish
peroxidase (HRP)
NA C-34780
* Approximate absorption (Abs) and fluorescence emission (Em) maxima, in nm. NA = Not
applicable.
Cholera toxin from Vibrio cholerae is comprised of two sub-
units, A and B, arranged in an AB5
configuration. The A subunit
is an ADP-ribosyltransferase, which disrupts the proper signal-
ing of G proteins and eventually leads to dehydration of the cell.
1
The nontoxic B subunit is important to the protein complex as it
allows the protein to bind to cellular surfaces via the pentasac-
charide chain of ganglioside GM1
.
2
At neutral pH, the 11.4 kDa
B subunit exists as a 57 kDa pentamer.
3
The B subunit of cholera toxin (CT-B) has proven to be a
powerful tool for retrograde labeling of neurons.
4,5
This tracer
has been used in a variety of applications, including tracing of ra
forebrain afferents,
6
projections of the parabrachial region 7
and
neurons of the urinary bladder wall.
8
More recently, researchers
have found that CT-B can be used as a marker for lipid rafts,
which are membrane microdomains enriched in cholesterol and
sphingolipids. Lipid rafts segregate specific groups of proteins
and thereby provide a hub for cellular signaling and protein traf-
ficking.
9, 10
Molecular Probes’ CT-B conjugates (Table 1) are made from
recombinant cholera toxin subunit B. Because the B-subunit
source material is recombinant in origin, it is extremely pure and
compley free of the toxic A subunit.
powder in 0.1 mL or 0.5 mL of buffer, for example, phosphate-
buffered saline (PBS). With the addition of 2 mM sodium azide,
solutions can be stored at 2–6°C for approximay three months.
For longer storage, divide the solution into aliquots and freeze at
≤–20°C.
The peroxidase conjugates of cholera toxin B are supplied in a
unit size of 100 µg. When stored desiccated at –20°C, the lyo-
philized powder is stable for at least six months. Solutions of
1.0 mg/mL can be prepared by dissolving the powder in 0.1 mL
of PBS, pH 7.2. Store solutions at 2–6°C with the addition of
thimerosal to a final concentration of 0.02%. DO NOT USE
AZIDE for the HRP-conjugates. For prolonged storage after re-
constitution, add glycerol to a final concentration of 50% (v/v),
aliquot and store at –20°C. When stored properly, solutions are
stable for approximay three months. PROTECT FROM
LIGHT. AVOID REPEATED FREEZING AND THAWING OF
SOLUTIONS.
For the Alexa Fluor and biotin conjugates, the lot-specific
degree of labeling (typically 5–10 moles of dye per mole of the
B subunit pentamer) is indicated on the product label.
Product List Current prices may be obtained from our Web site or from our Customer Service Department.
Cat # Product Name Unit Size
C-34775 cholera toxin subunit B (recombinant), Alexa Fluor? 488 conjugate .......................................................................................... 100 µg
C-22841 cholera toxin subunit B (recombinant), Alexa Fluor? 488 conjugate .......................................................................................... 500 µg
C-34776 , Alexa Fluor? 555 conjugate .......................................................................................... 100 µg
C-22843 , Alexa Fluor? 555 conjugate .......................................................................................... 500 µg
C-34777 , Alexa Fluor? 594 conjugate .......................................................................................... 100 µg
C-22842 , Alexa Fluor? 594 conjugate .......................................................................................... 500 µg
C-34778 , Alexa Fluor? 647 conjugate .......................................................................................... 100 µg
C-34779 , biotin-XX conjugate ....................................................................................................... 100 µg
C-34780 , horseradish peroxidase conjugate ........................................................ ........................ 100 µg
Materials
The biotin- and dye-labeled cholera toxin B subunits are sup-
plied in unit sizes of 100 µg and 500 µg. When stored desiccated
at ≤–20°C, these products are stable for at least six months.
Solutions of 1.0 mg/mL can be prepared by dissolving the
Due to the diversity of applications for the cholera toxin sub-
unit B, please consult the primary literature for appropriate work-
ng concentrations.
References
1. J Biol Chem 255, 1252 (1980); 2. Mol Microbiol 13, 745 (1994); 3. Biochemistry 35, 16069 (1996); 4. Brain Res 243 215 (1982); 5. Brain Res 231, 33
(1982); 6. Neuroscience 82, 443 (1998); 7. Brain Res 816, 364 (1999); 8. Neuroscience 87, 275 (1998); 9. J Cell Biol 147, 447 (1999); 10. J Cell Biol 141, 929
(1998).