Abstract: The invention provides novel retroviral vectors that have enhanced transcription termination structures. The termination structures comprise one or several heterologous upstream transcription termination enhancer (UE) sequences, or one or more additional copies of endogenous UE sequences operably associated with the 3′ LTR polyadenylation signal. The retroviral vectors of the invention have various improved properties over conventional vectors, including stronger gene expression, enhanced vector titer and reduced interference with host cell gene expression resulting from read-through of vector initiated transcriptional events.

Abstract: The invention concerns a process for preparing biological samples for the subsequent detection of an analyte. In particular, the invention relates to a process for the isolation of a nucleic acid in a sample using a suspension of magnetic glass particles. In addition, kits and apparatuses containing magnetic glass particles for sample preparation are provided.

Abstract: The invention concerns a method for the modification, cloning and amplification of cDNAs which are complete at their 5′ end which is essentially characterized in that the first strand cDNA synthesis is carried out in the presence of manganese2+ ions or manganese2+ is added as an additive at a later time. The CAP structure at the 5′ end of the reversely transcribed mRNA triggers the attachment of deoxy-cytosines to the 3′ end of the cDNA with high efficiency. In a preferred embodiment a controlled ribonucleotide tailing is carried out with the aid of terminal transferase following the first strand cDNA synthesis.

Abstract: Preparations of particles having a glass surface, wherein more than 75% by weight of these particles have a particle size between 0.5 &mgr;m and 15 &mgr;m and a glass surface which contains between 2 and 6 mole % zinc oxide, have proven to be particularly advantageous in processes for the purification of nucleic acids. This in particular results in an increased nucleic acid yield.

Abstract: The present invention is directed to a process for amplifying any target nucleic acid sequence contained in a nucleic acid or mixture thereof using a thermostable enzyme. The process comprises treating separate complementary strands of the nucleic acid with a molar excess of two oligonucleotide primers, extending the primers with a thermostable enzyme to form complementary primer extension products which act as templates for synthesizing the desired nucleic acid sequence, and detecting the sequence so amplified. The steps of the reaction can be repeated as often as desired and involve temperature cycling to effect hybridization, promotion of activity of the enzyme, and denaturation of the hybrids formed.

Abstract: The present invention provides reversibly blocked primers for use in the amplification of a nucleic acid sequence. Amplifications carried out using the blocked primers result in less non-specific amplification product, in particular, primer dimer, and a concomitant greater yield of the intended amplification product compared to amplifications carried out using unblocked primers.

Abstract: The present invention discloses functional and selectable micro-Ti plasmids. The hygromycin phosphotransferase (aphIV) gene from Escherichia coli was inserted between the 5' promoter and associated amino terminal region-encoding sequence of an octopine synthetase gene and the 3' terminator signal sequence of a nopaline synthetase gene. These constructs were assembled between T-DNA border fragments in a broad-host-range vector and used to create antibiotic-resistant plant cells.