PubMed Health⌕ Search

PubMed · 11204139

Conventional versus molecular diagnostic tests.

Abstract

In this session, emphasis was placed on the diagnosis of various mycoses through the identification of antibodies and antigens in sera, as well as on new techniques to properly identify medically important fungi through molecular biological procedures. The use of restriction fragment length polymorphism (RFLP) on fungal mitochondrial DNA (mtDNA) has enabled the identification of different strains of Sporothrix schenkii, several dermatophytes, Candida spp. and black fungi according to their species-specific mtDNA-RFLP patterns. In some species, distinct specific types where found in relation to the geographic origin of the patients. These particular molecular diagnostic tests are useful in the identification of strains and in epidemiological studies. An account of the applications of serological methods in the diagnosis of paracoccidioidomycosis was presented. Serology has been used in the identification of paracoccidioidomycosis using a specific, sensitive and rapid antibody-based immunodiagnosis method. Using the gp43 antigen, the diagnostic coverage of inmunodifussion has been improved from the 93-95% achieved with crude antigens, to 100% in an enzyme-linked immunodiffusion assay capture test. Cross-reactions were eliminated by treatment of the antigen with sodium metaperiodate. Antibody detection is useful, especially in paracoccidioidomycosis and histoplasmosis.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M R Elias Costa, C Da Silva Lacaz, M Kawasaki, Z P De Camargo. 2000. Conventional versus molecular diagnostic tests.. https://pubmed.ncbi.nlm.nih.gov/11204139/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

An RNA ligase-mediated method for the efficient creation of large, synthetic RNAs.

RNA ligation has been a powerful tool for incorporation of cross-linkers and nonnatural nucleotides into internal positions of RNA molecules. The most widely used method for template-directed RNA ligation uses DNA ligase and a DNA splint. While this method has been used successfully for many years, it suffers from a number of drawbacks, principally, slow and inefficient product formation and slow product release, resulting in a requirement for large quantities of enzyme. We describe an alternative technique catalyzed by T4 RNA ligase instead of DNA ligase. Using a splint design that allows the ligation junction to mimic the natural substrate of RNA ligase, we demonstrate several ligation reactions that appear to go nearly to completion. Furthermore, the reactions generally go to completion within 30 min. We present data evaluating the relative importance of various parameters in this reaction. Finally, we show the utility of this method by generating a 128-nucleotide pre-mRNA from three synthetic oligoribonucleotides. The ability to ligate synthetic or in vitro transcribed RNA with high efficiency has the potential to open up areas of RNA biology to new functional and biophysical investigation. In particular, we anticipate that site-specific incorporation of fluorescent dyes into large RNA molecules will yield a wealth of new information on RNA structure and function.

Genetic Techniques↗

Development and evaluation of HIV-1 subtype RNA panels for the standardization of HIV-1 NAT assays.

Multiple nucleic acid-based techniques (NAT) have been implemented for testing blood and plasma donors for HIV-1 RNA which may be detected at an earlier stage of infection when HIV antigen or antibody is absent or below the limit of detection of current assays. The available NAT assays are based on different technologies. In order to evaluate the performance of nucleic acid-based techniques (NAT assays) and to allow accurate comparisons of results from different assays, it is essential to have well characterized specimens with known copy numbers as a standard. For this purpose, a comprehensive study was conducted to develop two HIV-1 RNA reference panels. The first (Panel 1) was prepared using a single specimen from the HIV-1 group M subtype B and consists of panel members with a wide range of HIV-1 RNA copy numbers. Panel 2 consists of 26 members representing HIV-1 group M subtypes A, C, D, E, F, G and groups O and N. For accurate determination of HIV-1 RNA copy numbers of each member of Panel 2, they were analyzed using various testing platforms/technologies available through the cooperation of five independent laboratories participating in the study. A consensus value for HIV RNA copy number was assigned to each member of Panel 2 based on statistical analysis of the data provided by the participants. Both panels could serve as reference panels to be used by manufacturers of HIV NAT tests to evaluate the sensitivity limits of their assays.

Genetic Techniques↗

Unique reconstruction of tree-like phylogenetic networks from distances between leaves.

In this paper, a class of rooted acyclic directed graphs (called TOM-networks) is defined that generalizes rooted trees and allows for models including hybridization events. It is argued that the defining properties are biologically plausible. Each TOM-network has a distance defined between each pair of vertices. For a TOM-network N, suppose that the set X consisting of the leaves and the root is known, together with the distances between members of X. It is proved that N is uniquely determined from this information and can be reconstructed in polynomial time. Thus, given exact distance information on the leaves and root, the phylogenetic network can be uniquely recovered, provided that it is a TOM-network. An outgroup can be used instead of a true root.

Genetic Techniques↗