Abstract: Disclosed are compositions and methods for sensitive detection of one or multiple analytes. In general, the methods involve the use of special label components, referred to as reporter signals, that can be associated with, incorporated into, or otherwise linked to the analytes. In some embodiments, the reporter signals can be altered such that the altered forms of different reporter signals can be distinguished from each other. In some embodiments, sets of reporter signals can be used where two or more of the reporter signals in a set have one or more common properties that allow the reporter signals having the common property to be distinguished and/or separated from other molecules lacking the common property.

Abstract: Highly sensitive methods for assaying for biopolymers, such as by immunoassay or nucleic acid probe hybridization assay, and compositions for carrying out the methods, are provided. The methods employ as reporter group a RNA capable of being autocatalytically replicated by an RNA-dependent RNA polymerase, such as the replicase of bacteriophage Q.beta.. The high sensitivity of the assay methods is due to the rapid, exponential increase in concentration of such a replicative RNA, associated specifically with biopolymer analyte, that can be achieved by autocatalytic RNA replication.

Abstract: Repetitive DNA sequences of the protozoan parasites T. cruzi and P. falciparum have been isolated. These sequences appear more than once in the parasitic organism. Once isolated, the DNA sequences may be labelled with materials such as chromogens, biotin, or radioactive substances. The sequences may be used, in labelled or unlabelled form, as probes for the parasites.

Abstract: The present invention provides a method for detection of protozoan parasites in blood or other specimen from their mammalian hosts. The method comprises nucleic acid hybridization of repetitive nuclear DNA fragments of the parasites. Hybridization probes have been prepared for this purpose by cloning the repetitive nuclear elements that are species-specific in appropriate vectors. The sensitivity of these probes has been increased by further sub-cloning to make them capable of cascade hybridization. The assay is highly specific and sensitive for detection of disease-causing protozoan parasites of the commonly occurring Trypanosomatidae of the genus Leishmania and genus Trypanosoma, as well as for malaria-causing protozoan and other parasitic microorganims of mammals.

Abstract: Genetically engineered plasmids which express DNA encoding for insect stage specific glycoproteins of Trypanosoma cruzi are disclosed. The glycoproteins offer potential diagnostic utility for the detection of Chagus disease.