IntroductionPeriodate, iodate and bromate are important oxidants which can oxidize many inorganic and organic compounds. These ions have been extensively used as ingredients for indicators in catalytic-kinetic analysis involving redox processes. Iodate and bromate have been reported to be toxic ions. 1,2 The major rout of enviromental exposure to these oxihalides is drinking water. Bromate is a by-product of bromide containing water ozonization. Iodide ions may be found in brakish water and, to a lesser extent, in freshwater, and may form iodate during ozonization. Therefore, their determinations are required for enviromental protection.Several methods have been reported for the determination of periodate, iodate and bromate in mixtures. These include the spectrophotometric determination of periodate-iodate mixtures, [4][5][6] spectrophotometric, 7-9 chromatographic 10,11 and polarographic 12 determination of iodate-bromate and periodatebromate mixtures. To the best of our knowledge, there is only one report concerning the determination of ternary mixture of periodate, iodate and bromate.Kavalenties 13 determined periodate, iodate and bromate mixtures by means of 3,4-dihydroxybenzaldehyde guanylhydrazone (3,4-DHGB). Periodate, iodate and bromate oxidized 3,4-DHGB in slightly acidic medium, in 0.1 M HClO4 medium and in 20% HClO4, respectively. The absorbance of the oxidized 3,4-DHGB was measured at 420 nm. Periodate, iodate and bromate could be determined in the ranges of 1 -30, 0.5 -16 and 0.4 -14 µg/ml, respectively.In this paper we describe a rapid, simple, precise and accurate method for the spectrophotometric determination of periodate, iodate and bromate ions in mixtures. The method is based on the reaction of periodate, iodate and bromate with iodide in acidic media at three different pH values. Experimental ApparatusA Shimadzu Model UV-265 UV-Visible recording spectrophotometer with 1-cm glass cells was used for absorbance measurements. ReagentsTriply distilled water and analytical-reagent grade chemicals were used.Standard solutions of periodate, iodate and bromate were prepared by dissolving an appropriate amount of sodium periodate, sodium iodate and potassium bromate (all from Merck) in water. A 0.15 M iodide solution was prepared by dissolving 5.625 g sodium iodide (Merck) in water and diluting to the mark in a 50-ml volumetric flask. Citrate buffer solutions (0.1 M) of pH 6 and 3.3 were prepared from sodium citrate, sodium hydroxide and hydrochloric acid solutions and 0.1 M glycine buffer solution of pH 1 was prepared from glycine and hydrochloric acid solutions. ProceduresThree runs were needed for each sample. In the first run, an aliquot of a solution containing 1.5 -17 µg of periodate, 1.0 -18 µg of iodate and 2.0 -120 µg of bromate was transferred into a 10 ml volumetric flask. Then, a 2 ml volume of a pH 6.0 buffer solution was added. The solution was diluted to ca. 9 ml with water and 1.0 ml of a 0.15 M iodide solution was added. A stopwatch was started just after the addition of the iodide s...

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A set of unique sequences in bacterial genomes, responsible for protecting bacteria against bacteriophages, has recently been used for the genetic manipulation of specific points in the genome. These systems consist of one RNA component and one enzyme component, known as CRISPR (“clustered regularly interspaced short palindromic repeats”) and Cas9, respectively. The present review focuses on the applications of CRISPR/Cas9 technology in the development of cellular and animal models of human disease. Making a desired genetic alteration depends on the design of RNA molecules that guide endonucleases to a favorable genomic location. With the discovery of CRISPR/Cas9 technology, researchers are able to achieve higher levels of accuracy because of its advantages over alternative methods for editing genome, including a simple design, a high targeting efficiency and the ability to create simultaneous alterations in multiple sequences. These factors allow the researchers to apply this technology to creating cellular and animal models of human diseases by knock‐in, knock‐out and Indel mutation strategies, such as for Huntington's disease, cardiovascular disorders and cancers. Optimized CRISPR/Cas9 technology will facilitate access to valuable novel cellular and animal genetic models with respect to the development of innovative drug discovery and gene therapy.