The means by which superfamilies of specialized enzymes arise by gene duplication and functional divergence are poorly understood. The escape from adaptive conflict hypothesis, which posits multiple copies of a gene encoding a primitive inefficient and highly promiscuous generalist ancestor, receives support from experiments showing that resurrected ancestral enzymes are indeed more substrate-p...

The use of the alkaline phosphatase (AP) as an enzyme label and the amplification of its analytical response with a diaphorase (DI) secondary enzyme were investigated in an electrochemical hybridization assay involving arrays of carbon screen-printed DNA biosensors for the sensitive quantification of an amplified 406-base pair human cytomegalovirus DNA sequence (HCMV DNA). For this purpose, PCR...

It is possible to perform a combined amplification and sequencing reaction ('DEXAS') directly from complex DNA mixtures by using two thermostable DNA polymerases, one that favours the incorporation of deoxynucleotides over dideoxynucleotides, and one which has a decreased ability to discriminate between these two nucleotide forms. During cycles of thermal denaturation, annealing and extension, ...

We present a continuous-flow droplet-based digital Enzyme-Linked Oligonucleotide Hybridization Assay (droplet digital ELOHA) for sensitive detection and absolute quantification of RNA molecules. Droplet digital ELOHA incorporates direct hybridization and single enzyme reaction via the formation of single probe-RNA-probe (enzyme) complex on magnetic beads. It enables RNA detection without revers...

background and purpose :candidiasis is a widespread fungal infection caused by different candida species. rapid identification of candida species in clinical laboratory is becoming increasingly important since the identification and discrimination of ethological agents for early treatment. we aimed at molecular identification of commonly candida species isolated from clinical samples by using b...

objective(s) staphylococcus aureus is both a successful human commensal and a major pathogen. in this study we investigated the genetic diversity of 26 s. aureus isolates recovered from human skin and urinary tract infections. materials and methods typing procedure for the studied s. aureus isolates was performed based on pcr amplification of the aroa gene, which encodes the enzyme 5-enolpyruvy...

Halobacterium volcanii mutants that are resistant to the dihydrofolate reductase inhibitor trimethoprim contain DNA sequence amplifications. This paper describes the cloning and nucleic acid sequencing of the amplified DNA sequence of the H. volcanii mutant WR215. This sequence contains an open reading frame that codes for an amino acid sequence that is homologous to the amino acid sequences of...

A partial amino acid sequence of a serine protease from Dermatophilus congolensis allowed the design of oligonucleotide primers that were complemented with additional ones from previously published partial sequences of the gene encoding the enzyme. The polymerase chain reaction (PCR), using combinations of specific and degenerate oligonucleotide primers, allowed the amplification of a 1738-bp i...

Third-generation enzyme immunoassays start to de tect anti-HIV antibodies within 20–22 days after exposure; fourthgeneration enzyme immunoassays, which test for p24 antigen and anti-HIV antibodies, can yield positive re sults within 16–18 days. RNA nucleic acid amplification testing starts to de tect HIV infection within 7–14 days. At $75 per test, these RNA tests are too costly for routine use...

Compromised biological evidence, particularly those samples that contain a very small amount of DNA or may have a significant amount of degradation, may not yield a complete or useful DNA profile. One approach that shows promise to overcome the limited quantity of DNA issue is the use of Whole Genome Amplification (WGA). The WGA method amplifies all the DNA in a sample, yielding higher levels o...