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The first step of the Adleman-Lipton extract model in DNA computing is the combinatorial generation of libraries. In this paper a new method is proposed for generating a initial pool, it is a quaternary recombination of strings via application of null context splicing rules. Its implementation, based on a kind of PCR called XPCR, results to be convenient with respect to the standard methods, in terms of efficiency, speed and feasibility. The generation algorithm we propose was tested by a lab experiment here described, since the presence of few sequences is enough for checking the completeness of the library. The simple technology of this approach is interesting in and of itself, and it can have many useful applications in biological contexts. Keywords: SAT, PCR, XPCR, generation of DNA initial pool. [ABSTRACT FROM AUTHOR]

The extraction of DNA strands including a given sequence of bases is a crucial step in the Adleman-Lipton extract model of DNA computing. In this paper, a special type of PCR is presented with a related algorithm which performs a specified extraction from a given pool of DNA double stranded (shortly dsDNA) molecules. This kind of PCR, called Cross Pairing PCR (shortly XPCR) was tested in several situations, and used in a biotechnological procedure which implements the extraction algorithm. [ABSTRACT FROM AUTHOR]

Adhesion molecules mediate recognition of the blood vessels by circulating leukocytes and support their selective targeting to different organs (1). In the vessels, the blood flow imposes peculiar conditions by generating a wall shear stress that opposes leukocyte stable arrest on the endothelium. As the rapidness of integrin activation is mandatory to leukocyte adhesion to the blood vessels, any analysis of adhesion triggering relevant to leukocyte in vivo migration should be performed under flow conditions. Here, a method is illustrated to quantitatively analyze the rapid induction of integrin-dependent lymphocyte adhesion by chemokines under flow conditions. Glass capillary tubes are cocoated with purified ligands for selectins and integrins and with chemokines, thus reconstituting the minimal requirement to support tethering, rolling, and arrest under flow conditions, with a physiologic wall shear stress of 2 dynes/cm2. PNAd, ICAM-1, and the chemokine CCL21 are used as paradigmatic adhesion molecules and physiologic proadhesive agonist. Naive lymphocytes isolated from mouse lymph nodes are used as the cell model. The procedure for quantitative analysis is discussed. [ABSTRACT FROM AUTHOR]