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This infоrmаtiоn is fоr questions 15–22. The following is from а published (Sept. 2014) purificаtion scheme for the isolation of a toxic protein from the venom of the blunt-nosed viper, a snake native to North Africa. Answer the following questions about the techniques used to purify and characterize the protein. Text from the reference cited below: “2.2. Purification of lebecinAbout 300 mg of crude venom of M. lebetina was dissolved in a small volume of 0.2 M ammonium acetate, pH6.8, applied to a column packed with Sephadex G-75 equilibrated with the same buffer (Pharmacia, Uppsala, Sweden) and eluted as previously described ( Sarray et al., 2003). The fraction II, containing anti-adhesive activity, was pooled and lyophilized for further purification. It was applied on a Mono S (HR5/5) column previously equilibrated with 50 mM HEPES/HCl pH 7.5 and eluted with linear NaCl gradient (0-1 M) at a flow rate of 1 ml/min. Finally, the fractions obtained were purified on C8 column (250 x 4.6 mm, 5 mm; Beckman) by reversed phase HPLC equilibrated in 0.1% trifluoroacetic acid (TFa) in 10% acetonitrile and elution was achieved using a linear acetonitrile gradient (10-80%) at a flow rate of 1 ml/min. Proteins concentration of purified lebecin was quantified according to the protocol provided by the BCA kit (Pierce Chemical Co.) using bovine serum albumin (BSA) as a standard. The homogeneity and the apparent molecular mass of the purified lebecin and its subunits were determined by SDS_PAGE method using 12.5% polyacrylamide gel with or without reduction by 2% beta-mercapto-ethanol. Proteins were stained with Coomassie brilliant blue R-250 (Sigma). Purified lebecin was reduced and alkylated as described previously by Sarray et al. (2003). The S-alkylated proteins chains were then desalted and separated by reverse phase HPLC on a C8 column as described above for protein purification. 2.3. N-terminal amino acid sequence determinationThe N-terminal amino acid sequences of lebecin subunits were determined by automated Edman degradation using a PROCESE instrument from Applied Biosystem (Foster city, CA). Sequence homology was evaluated by a computer search in the protein sequence database (BLAST search).” Jebali, J., Fakhfekh, E., Morgen, M., Srairi-Abid, N., Majdoub, H., Gargouri, A., El Ayeb, M., Luis, J., Marrakchi, N., & Sarray, S. (2014). Lebecin, a new C-type lectin like protein from Macrovipera lebetina venom with anti-tumor activity against the breast cancer cell line MDA-MB231. Toxicon : official journal of the International Society on Toxinology, 86, 16–27.