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Introduction & Objective: Primer-Template hybridization temperature is one of the important parameters in Nested PCR optimization. Unlike instant temperature for sequence amplification in routine PCR process, Touchdown PCR is a modified form of standard PCR that employs a range of annealing temperature. This study intended to develop a Touchdown Nested PCR in order to circumvent spurious priming and enhancing specify during gene amplification. Materials & Methods: This is an experimental study conducted at Tarbiat Modarres University of Tehran during 2008-2009. Study samples were collected from Digestive Diseases Research Centre- at Shari'ati Hospital and HIV research center – Imam Khomeini Hospital. After extracting the nucleic acid, primer designing for HIV and GBV-C and c-DNA synthesis Nested PCR was performed on negative and positive samples using standard and touchdown protocols. Results: The intended band was observed in all positive samples. No band was observed in any human and viral negative control samples. After electrophoresis of PCR products, non specific band were seen in HIV and GBV-C samples during standard PCR. Using the touchdown protocol, undesirable bands were omitted or significantly decreased. Conclusion: In the present study, despite the formation of uncalled bands in standard reaction using the touchdown method led to omission of non-specific bands without any significant effect on the final products. As for its simplicity, cost and time saving, it seems that using this method is a rational and economical way for fast optimization of PCR reactions.

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Abstract Background & aim: Islamic Republic of Iran is one of the well-known foci of malaria in Eastern Mediterranean Region.The study was carried out to investigate malaria situation in Kogiloye and Boyerahmad during during 2001-2010. Methods: The retrospective study using data information were extracted from health center of archived from malaria cases had been recorded in province during the years of 2001-2010 .The data were analyzed by Descriptive statistical test. Results: Out of one hundred and fifty six malaria cases during this decade, 119 (76.28%) were males and 37 (23.7%) females. The study showed that about 87% of malaria cases had been occurred in Afghanian immigrants in this region. The highest and lowest (29.6% vs.1.9%) rates of malaria were occurred in 2002 and 2010 , respectively. Among districts of the province the highest rate of malaria cases was belonged to Boyerahmad (80.1%).The present study indicated that Plasmodium vivax was the most common cause of malaria in this region ( 91.02%) followed by P.falciparum ( 8.33%). Conclusion: During the past decade malaria cases were apparently decreased in Kohgiloye and Boyerahmad province and most of cases had been imported to the region from other endemic foci. Respect to suitable environmental conditions for transmission of malaria in this area surveillance measures should be implicated to control disease through rapid diagnosis and treatment of patients particularly in foreign immigrants. Key words: Malaria, P.Vivax , P.Falciparum