In vitro: |
Biosens Bioelectron. 2015 Apr 18;71:256-260. | Development of ELISA and colloidal gold immunoassay for tetrodotoxin detetcion based on monoclonal antibody.[Pubmed: 25913446] | METHODS AND RESULTS: A monoclonal hybridoma cell named 5B9 against tetrodotoxin (TTX) was obtained after fusion of myeloma SP2/0 cells with spleen cells isolated from the immunized Balb/c mice. The 5B9 monoclonal antibody (McAb) with high affinity (about 2.55 × 10(9)) is specific to TTX, and this McAb belongs to the immunoglobulin G (IgG) isotype. Finally, an enzyme-linked immunosorbent assay (ELISA) and colloidal gold immunoassay were established based on this McAb. The linear range of ELISA to detect TTX was 5-500 ng/mL, and the limit of detection (LOD) was 4.44 ng/mL. The average CV of intra- and inter-assay was less than 8%, with the samples recovery range of 70.93-99.99%. A competitive format colloidal gold strip was developed for detection of TTX in real samples, and the LOD for TTX is 20 ng/mL, and the assay time of the qualitative test can be finished in less than 10 min without any equipment. CONCLUSIONS: The result from test strip revealed that the test strip has a good agreement with those obtained from ELISA. | J Gen Physiol. 1964 May;47:965-74. | TETRODOTOXIN BLOCKAGE OF SODIUM CONDUCTANCE INCREASE IN LOBSTER GIANT AXONS.[Pubmed: 14155438] | Previous studies suggested that Tetrodotoxin, a poison from the puffer fish, blocks conduction of nerve and muscle through its rather selective inhibition of the sodium-carrying mechanism. METHODS AND RESULTS: In order to verify this hypothesis, observations have been made of sodium and potassium currents in the lobster giant axons treated with Tetrodotoxin by means of the sucrose-gap voltage-clamp technique. Tetrodotoxin at concentrations of 1 x 10 -7 to 5 x 10 -9 gm/ml blocked the action potential but had no effect on the resting potential. Partial or complete recovery might have occurred on washing with normal medium. The increase in sodium conductance normally occurring upon depolarization was very effectively suppressed when the action potential was blocked after Tetrodotoxin, while the delayed increase in potassium conductance underwent no change. CONCLUSIONS: It is concluded that Tetrodotoxin, at very low concentrations, blocks the action potential production through its selective inhibition of the sodium-carrying mechanism while keeping the potassium-carrying mechanism intact. |
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