Calf thymus dna

Tnz was purchased
from Sigma-Aldrich
and purified by re-crystallization from methanol. Copper(II) chloride
(CuCl₂·2H₂O), copper(II) acetate [Cu(OAc)₂·H₂O], NaCl, NaNO₃, trichloroacetic
acid (TCA), glacial acetic acid, sodium dihydrogen phosphate, disodium
hydrogen phosphate, anthrone as reagent, Folin-Ciocalteu as reagent,
congo red, cetyltrimethylammonium bromide (CTAB), chitin flakes, Tris–HCl,
β-mercaptoethanol, phenylmethylsulfonyl fluoride (PMSF), and
KCl (all AR grade) were purchased from E. Merck, India. Thymine, cytosine,
and adenine were purchased from TCI, Japan, and calf thymus DNA, crystal
violet (CV), ethyl acetate, hydroxyl amine, NaOH, and ferric chloride
were procured from Sisco Research Laboratories, India. Calf thymus
DNA was dissolved in triple distilled water in the presence of 120
mM NaCl, 35 mM KCl, and 5 mM MgCl₂. Its concentration was
determined using a molar extinction coefficient of 6600 M^–1 cm^–1 at 260 nm. Absorbance of the DNA solution
was also measured at 280 nm; A₂₆₀/A₂₈₀ was determined. The value found in the range
1.8–1.9 was considered ready for use, not requiring further
purification. Quality of calf thymus DNA was verified using circular
dichroism (CD), recording its response at 260 nm on a CD spectropolarimeter
(J815—JASCO, Japan). Aqueous solutions of all other substances
were prepared in triple distilled water.

Alizarin was procured from Sigma and purified by re-crystallization using ethanol. The Mn^II complex of Alizarin [Mn^II(alz)₂(H₂O)₂] (Figure 1) was prepared and characterized earlier [55 ]. KCl (AR), purchased from Merck India, was used as an electrolyte for electrochemical experiments in aqueous medium. Nucleobases uracil, thymine and adenine were obtained from Sisco Research Laboratories, India; cytosine was obtained from Sigma. Calf thymus DNA was obtained from Sisco Research Laboratories, India. Tetrabutyl ammonium bromide (TBAB) (AR) and Ethidium bromide (EtBr) were purchased from Merck, India. Triple distilled water was used for preparing solutions. Phosphate buffer (pH ~ 7.4) was prepared in triple distilled water using sodium dihydrogen phosphate (AR) and disodium hydrogen phosphate (AR) procured from Merck, Germany.Figure 1

Structure of (A) Alizarin, (B) [Mn^II(alz)₂(H₂O)₂] and (C) an anthracycline anticancer drug.

Figure 1