Abstract: Linear or branched oligonucleotide multimers useful as amplifiers in biochemical assays which comprise (1) at least one first single-stranded oligonucleotide unit that is complementary to a single-stranded oligonucleotide sequence of interest, and (2) a multiplicity of second single-stranded oligonucleotide units that are complementary to a single-stranded labeled oligonucleotide. Amplified sandwich nucleic acid hybridizations and immunoassays using the multimers are exemplified.

Abstract: Novel phosphorylating reagents are provided which are useful in DNA synthesis and purification procedures. The reagents are substituted phosphines which are particularly useful in the phosphorylation of nucleoside and solid supported oligonucleotides at the 5'-hydroxyl position. Phosphorylation using these reagents is easily and accurately monitored colorimetrically.

Abstract: Novel photolabile photochemical reagents are disclosed. The reagents are useful in a variety of biochemical and chemical contexts, including nucleic hybridization assays and chemical phosphorylation of hydroxyl-containing compounds. The reagents are particularly useful for introducing cleavable sites into oligonucleotide or polynucleotide chains, i.e., sites which are cleavable upon photolysis. The reagents are also useful in both 5'- and 3'-phosphorylation of oligonucleotide or polynucleotide chains.

Abstract: Oligomers and polymers are prepared substantially free of error sequences by sequentially adding monomers, which are terminally blocked and have active functionalities protected, to a growing chain bound to a support through a selectively cleavable linkage. After each addition, unblocked terminal groups are capped. At the completion of monomer addition, enzymatic hydrolysis interfering protecting groups are removed along with the capping group and failure sequences enzymatically degraded. The terminal blocking group may then be removed. The completed oligomer or polymer may be cleaved from the support prior or subsequent to enzymatic degradation but after completion of the sequence.

Abstract: A method of phosphorylating a nucleoside or an oligonucleotide chain having a free 2', 3' or 5' hydroxyl moiety is provided. The method involves the use of a phosphorylating reagent which is selected such that the extent of phosphorylation can be monitored colorimetrically, easily and accurately. The phosphorylating reagent contains an aromatic species such as a dimethoxytrityl group that is cleavable with acid and colorimetrically detectable upon release.

Abstract: Linear or branched oligonucleotide multimers useful as amplifiers in biochemical assays which comprise (1) at least one first single-stranded oligonucleotide unit that is complementary to a single-stranded oligonucleotide sequence of interest, and (2) a multiplicity of second single-stranded oligonucleotide units that are complementary to a single-stranded labeled oligonucleotide. Amplified sandwich nucleic acid hybridizations and immunoassays using the multimers are exemplified.

Abstract: Modified nucleotides are provided which have the structure ##STR1## wherein R.sup.1 is a reactive group derivatizable with a detectable label, R.sup.2 is an optional linking moiety including an amide, thioether or disulfide linkage or a combination thereof, R.sup.3 is hydrogen, methyl, bromine, fluorine or iodine, R.sup.4 is hydrogen, an acid-sensitive, base-stable blocking group of an acyl capping group, R.sup.5 is hydrogen or a phosphorus derivative, R.sup.6 is H, OH, or OR where R is a protecting group and x is an integer in the range of 1 and 8 inclusive. Methods of synthesizing the derivatizable nucleotide are disclosed, as are labeled polynucleotide probes prepared therefrom.

Abstract: Modified nucleotides are provided which have the structure ##STR1## wherein R.sup.1 is a reactive group derivatizabale with a detectable label, R.sup.2 is an optional linking moiety including an amide, thioether or disulfide linkage or a combination thereof. R.sup.3 is hydrogen, methyl, bromine, fluorine or iodine, R.sup.4 is hydrogen, an acid-sensitive, base-stable blocking group or an acyl capping group, R.sup.5 is hydrogen or a phosphorus derivative, R.sup.6 is H, OH, or OR where R is a protecting group and x is an integer in the range of 1 and 8 inclusive. Methods of synthesizing the derivatizable nucleotide are disclosed, as are labeled polynucleotide probes prepared therefrom.

Abstract: A fuel injection fuel supply system for a combustion engine has a fuel injector valve effective for metering and injecting all of the required fuel to the engine induction system; in one version a single valve functions to supply the required fuel in equal amounts to each of the combustion cylinders of the engine through chamber means exposed to superatmospheric air; an electromagnetic assembly having a magnetic open loop is used for cyclically opening and closing the injector valve.