Abstract: An innovative detection system for detecting small numbers of target analytes is disclosed. This system provides a novel method for attaching multiple copies of reporter groups to a single site on an analyte of interest. This system preferably comprises a virus capsid enclosing multiple detectable reporter groups, and a linking molecule which is capable of linking the capsid to the analyte of interest.

Abstract: A method is described for detecting, selecting, and cloning agents that degrade DNA or promote DNA degradation. The method utilizes extra-chromosomal replicons whose replication is dependent on degradation of a host cell's DNA to screen for agents leading to degradation of cellular DNA. An agent which promotes degradation of a host cell's DNA enables the replicons to replicate, which signals the presence of agents that promote the cellular DNA degradation and allows for the isolation and amplification of such agents.

Abstract: An innovative detection system for detecting small numbers of target analytes is disclosed. This system provides a novel method for attaching multiple copies of reporter groups to a single site on an analyte of interest. This system preferably comprises a virus capsid enclosing multiple detectable reporter groups, and a linking molecule which is capable of linking the capsid to the analyte of interest.

Abstract: A method is described for detecting, selecting, and cloning agents that degrade DNA or promote DNA degradation. The method utilizes extra-chromosomal replicons whose replication is dependent on degradation of a host cell's DNA to screen for agents leading to degradation of cellular DNA. An agent which promotes degradation of a host cell's DNA enables the replicons to replicate, which signals the presence of agents that promote the cellular DNA degradation and allows for the isolation and amplification of such agents.

Abstract: A method is described for detecting, selecting, and cloning agents that degrade DNA or promote DNA degradation. The method utilizes extra-chromosomal replicons whose replication is dependent on degradation of a host cell's DNA to screen for agents leading to degradation of cellular DNA. An agent which promotes degradation of a host cell's DNA enables the replicons to replicate, which signals the presence of agents that promote the cellular DNA degradation and allows for the isolation and amplification of such agents.

Abstract: Inviable T4 phage-like particles capable of directing the expression of large non-T4 DNA fragments from T4 expression control sequences are produced. Thus, E. coli harboring pBR322 derivatives containing cloned T4 gene 23 DNA sequences were infected with T4 phage carrying a deletion of the denB gene. Homology-dependent recombination results in the production of inviable phage-like particles containing DNA molecules composed of multiple, tandemly repeated copies of entire plasmid molecules covalently linked to single copies of normal phage genes. The yield of these inviable particles, intially low, was increased by means of a reiterated infection process that involves the use of a cloned T4 origin of replication. When T4 gene 32 expression control sequences linked in proper orientation to a DNA sequence coding for the non-T4 protein .beta.-galactosidase were also cloned in one such pBR322 derivative (pVH773), inviable phage particles capable of directing the synthesis of enzymatically active .beta.