da li neko zna kako nastaje?hitno!
mislila sam da ovo znam iz organske,ali sam se grdno prevarila...mislila sam na formozu,zato se do sada nisam javljala...mozda je sada kasno,ali ce valjda nekom drugom koristiti PREUZETO SA SAJTA WIKIPEDIJE
Formazan dyes are artificial chromogenic substrates for dehydrogenases and reductases. They are formed from reduction of tetrazolium salts, including INT (2-(4-Iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride), MTT (3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide) (used in the MTT assay), and the more water soluble XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide). When reduced in a cell, either enzymatically or through direct reaction with NADH or NADPH MTT turns bright blue and may form an insoluble precipitate.
These formazan dyes are commonly used in cell proliferation and toxicity assays like the EpiSkin test since they only stain living cells.
Formazans are produced when tetrazolium salts such as MTS, MTT, INT and XTT are reduced by naturally occurring enzymes. They have a variety of colors from dark blue to deep red to orange, depending on the tetrazolium salt. They can be water soluble or non-water soluble.
RECJU,FORMAZANI NASTAJU REDUKCIJOM TETRAZOLIJUM SOLI.sluze kao supstrat za hidrogenaze i reduktaze.u celiji u organizmu se se stvaraju enzimski ili direktno u reakciji sa NADH I NADPH.koriste se u testovima toksicnosti i celijskim proliferacijama...primer-EPIskin test.formazani su razlicitih boja,od tamno plave do crvene i narandzaste,a sve u zavisnosti od koje soli poticu...itd.
:cvet
inace formazan se moze meriti spektrofotometrijski na 490 nm...zato je i pogodan ...njegova jedinjenja mogu biti rastvorna i nerastvorna u vodi...neka me neko ispravi,dopuni... :help2:
Neka neko postavi kako je bilo kod prof. Brizite i pitanja koja je imao... Hvala....
e, pa ima ta reakcija u praktikumu iz analitike lekova, sad sam provalila, a svo vreme mi bilo od nekud poznato.. :cvet