Application
Cholera toxin B subunit conjugated to peroxidase (CB-HRP) has been shown to be a more effective retrograde and transganglionic tracer for pelvic primary afferents from the urinary bladder than wheat germ agglutinin-horseradish peroxidase or isolectin B4-horseradish peroxidase. Retrograde labeling with CB-HRP has been demonstrated in symphathetic pre-ganglionic neurons as well as in cells of the fastigial nuclei. It is also an effective anterograde tracer for the study of axonal and terminal labeling in brain stem.
Caution
Do not freeze.
Packaging
Prepared and packaged using aseptic technique and sealed under vacuum.
Reconstitution
Reconstitution of the vial with 100 μl of water will yield a final solution containing: 1 mg/mL HRP, 0.45 mg/ml CTB, 10 mM phosphate buffer and 150 mM NaCl. Swirl bottles gently during reconstitution. Avoid vigorous pipetting of solutions that may lead to foaming. Solutions can be sterile filtered through a 0.2 μm filter. Store the reconstituted solutions at 2-8 °C.
Specificity
HRP activity exceedes 100 pyrogallol units per mg of HRP in the CTB-HRP conjugate. Activity: 10-30 pyrogallol units per vial.
Unit Definition
Unit definition: One pyrogallol unit converts 1 mg of pyrogallol to purpurogallin in 20 seconds at pH 6.0 at 20 °C.
Physical form
Lyophilized powder containing 11-13% protein with the balance consisting of phosphate buffer and sodium chloride.
Biochem/physiol Actions
The cholera toxin B subunit is used for track tracing in neurological research, taking advantage of GM1 ganglioside binding and retrograde transport. Tissue culture cells treated with cholera toxin are not killed and tissues of animals do not become necrotic. |