A related study in the same cohort examined the role of modeled levels of 24 mammary gland carcinogens (MGCs) at the residence and found associations between propylene oxide and vinyl chloride and overall breast cancer risk, as well as associations for acylamide, benzidine
, carbon tetrachloride, ethylidene dichloride, and vinyl chloride with ER + /PR + breast cancer and for benzene with ER--/PR--breast cancer (Garcia et al.
The substrate solution, tetramethyl benzidine
(100 [micro]l) was immediately added into each well followed by incubation at room temperature away from light for 20 minutes.
Sections were visualized with 3,3'-diamino benzidine
(DAB; Dako; Glostrup, Denmark).
After another rinsing, a dye consisting of tetra-methyl benzidine
and hydrogen peroxide was poured into the wells.
Results and Discussion Synthesis of Dyes 6a-j Synthesis of Congo red dye and its derivatives (6a-j) was achieved in excellent yields, according to the synthetic strategy outlined in scheme 1 starting from benzidine
A total of 100 [micro]l of Tetra Methyl Benzidine
(TMB) chromogenic substrate was then dispensed in to each well and the plates were then incubated for 30 minutes at room temperature.
Next, the enzyme substrate (3,3',5,5'-tetramethyl benzidine
peroxidase substrate and peroxidase solution B) was added, and the samples were incubated for 15 min (IgM) or 30 min (IgG).
Each sample was analyzed in duplicate using, peroxidase as the enzymatic tracer, a polyclonal antibody (L2) and tetramethyl benzidine
as color reagent (L2 antibodies have a six-to eightfold higher affinity for ecdysone than for 20E).
012g of 3,3,5,5 tetramethyl benzidine
dihydrochloride in 6 ml of methanol and 18 ml of 250 mM sodium acetate buffer at pH 5.
Those most commonly used in clinical biochemistry were aromatic amines such as benzidine
Excess HRP-conjugate is washed off and solution of tetra methyl benzidine
(TMP) reagent was added.
I noticed that one of the starting materials for the API resembled benzidine
(4,4'-diaminobiphenyl), a known carcinogen.