Study of new routes for purification of fission 99Mo

99mTc is the most applied medical radioisotope in the world, especially for cancer diagnosis procedures. It is provided by 99Mo radioactive decay, which is one of the fission products from the uranium irradiation in nuclear reactors. At the main production plants, the 99Mo chemical processing may be lined up in several steps to separate it from other fission products according to the features of the used targets or the local requirements as well. In this work, two routes of 99Mo purification, MR1, and MR2, were purposed as an alternative to be set up in the Brazilian Multipurpose Reactor project (BMR). The MR1 route was performed by three chromatographic columns packed with Dowex 1x8 resin, Chelex resin, and alumina, respectively. The route MR2 was carried out also by chromatography applying two columns filled with Dowex 1x8 and alumina respectively, but including a sublimation process performed in a tubular oven under programmed conditions. The final yield for the MR1 route was 84.4 % and the overall time process was about 7 hours, whereas the MR2 route reached 75.3 % in 9 hours.

BACTERIAL DNA EXTRACTION METHOD FOR THE DETECTION OF HELICOBACTER PYLORI FROM HUMAN FECAL SAMPLES

Objective: The work proposed the implementation of a method of DNA extraction for the detection of the pathogen from 50 stool samples. Methods: A method of DNA extraction with Chelex resin was applied and then detected by conventional polymerase chain reaction (PCR). Results: By PCR, 11 samples were positive for Helicobacter pylori. Conclusions: The Chelex extraction methodology allows obtaining DNA with quality necessary to be detected by PCR, making it a fast methodology for its diagnostic application.

Lipe gene polymorphism c.442 G>A influence on carcass traits in pigs

Hormone sensitive lipase is one of three enzymes involved in lipolysis process and encoded by LIPE gene. In this study we investigated LIPE gene polymorphism c.442 G>A influence on carcass traits in hybrid pigs. Genomic DNA extracted using Chelex resin, genotypes determined using RFLP-PCR. Allele A observed with frequency 0,738, allele G - 0,262. The most common genotype was AA, genotype GG was observed with lower frequency, genotype AG was rarest. While evaluating population heterozygosity, it was noticed that observed heterozygosity was only 0,075, while expected heterozygosity was 0,387. In observed pig population allele A is associated with better animal muscularity, allele G - with greater fat content.

Metal Toxicity Reduction in Naphthalene Biodegradation by Use of Metal-Chelating Adsorbents

ABSTRACT A model system comprising microbial degradation of naphthalene in the presence of cadmium has been developed to evaluate metal toxicity associated with polyaromatic hydrocarbon biodegradation and its reduction by the use of unmodified and surfactant-modified clays in comparison with a commercially available chelating resin (Chelex 100; Bio-Rad). The toxicity of cadmium associated with naphthalene biodegradation was shown to be reduced significantly by using the modified-clay complex and Chelex resin, while unmodified clay has no significant impact on this reduction. The degree of metal toxicity reduction can be quantitatively related to the metal adsorption characteristics of these adsorbents, such as adsorption capacity and selectivity.

Isolation of genomic DNA from milk samples by using Chelex resin

A rapid procedure for isolating genomic DNA from milk samples has been devised, based on the use of Chelex resin. By using this protocol, genomic DNA was extracted from milk samples from 15 cows and 15 goats. The suitability of these DNA preparations as a template for performing the polymerase chain reaction (PCR) was tested by amplifying three different loci of the bovine genome: exon 4 of the κ-casein gene and the INRA5 and INRA23 microsatellites, together with two others: exon 19 of the αs1-casein gene and exon 2 and part of intron 2 of the DRB gene of the caprine genome. No amplification products could be obtained from any samples at 30 cycles. In contrast, at 45 cycles the number of amplified samples ranged from 86 to 100% and at 65 cycles all the DNA targets were amplified, indicating that the number of cycles was a critical factor to be optimized for obtaining the desired PCR target. These results suggest that this method may be a useful tool for analysing genetic polymorphism at the DNA level by PCR and relating it to milk composition and other traits of economic interest.