An enzymatic paper-based biosensor for ultrasensitive detection of DNA.

Point-of-care Nucleic acid testing (POCNAT) has become an attractive technique for DNA identification in resource-limited settings, offering a rapid system for urgent clinical applications. In this study, a chemiluminescence-based lateral flow biosensor (CL-LFB) was developed for the quantitative analysis of DNA, without labeling and amplification. The developed biosensor employs a two-step hybridization, a primary hybridization of 5'-biotinylated detector probe to the target DNA and a secondary hybridization of the resulting complex with the immobilized capture probe.

Designing a new biosensor "DNA ELISA" to detect Escherichia coli using genomic DNA and comparison of this method to PCR-ELISA.

In this experiment, DNA-ELISA biosensor was introduced, bearing the ability to detect specific bacteria in about 4 h. This is a more rapid system in comparison to conventional methods, like colony counting method. Moreover, this method does not require any amplification and directly detects genomic DNA of bacteria, giving a lower limit to the sensitivity of 40,000 bacteria.

Voltammetric determination of the Escherichia coli DNA using a screen-printed carbon electrode modified with polyaniline and gold nanoparticles.

The authors describe an electrochemical assay for fast detection of Escherichia coli (E. coli). It is based on a dual signal amplification strategy and the use of a screen-printed carbon electrode (SPCE) whose surface was modified with a polyaniline (PANI) film and gold nanoparticles (AuNPs) via cyclic voltammetry (CV).

Retroviral transduction of fluonanobody and the variable domain of camelid heavy-chain antibodies to chicken embryonic cells.

Background: Single domain antibodies from camel heavy chain antibodies (VHH or nanobody), are advantages due to higher solubility, stability, high homology with human antibody, lower immunogenicity and low molecular weight. These criteria make them candidates for production of engineered antibody fragments particularly in transgenic animals.

Objective: To study the development of transgenic chicken using a recombinant retrovirus containing fluonanobody.

Induction of differentiation by down-regulation of Nanog and Rex-1 in cord blood derived unrestricted somatic stem cells.

Stem cells with high self-renewal and tissue regeneration potentials are the core components of regenerative medicine. Adult stem cells with many available sources, high repairing ability, and also possessing no ethical issues are popular candidates in the clinical field. In this study we looked upon the effects of two transcription factors Nanog and Rex-1 in self-renewal and differentiation abilities of a subpopulation of cord blood stem cells known as unrestricted somatic stem cells (USSCs).

Production of Pentameric Cholera Toxin B Subunit in Escherichia coli.

Cholera toxin B subunit (CTB) has been extensively studied as an immunogen, adjuvant, and inducer of oral tolerance in many investigations. Production of CTB has been carried out in the bacterial, plant, insect and yeast expression systems. In this study the expression of the CTB containing a 6XHis-tagged was performed by Escherichia coli (E.

Tropisetron upregulates cannabinoid CB1 receptors in cerebellar granule cells: possible involvement of calcineurin.

Tropisetron, a selective 5-HT(3) receptor antagonist, is widely used to counteract chemotherapy-induced emesis. Some investigations describe disparate effects including immunomodulatory properties for tropisetron which may be mediated through immunophilin-calcineurin pathway. Calcineurin, a phosphatase involved in immune system signaling, modulates expression of several genes, such as Cannabinoid type one (CB(1)) receptors.

Functional Concentrations of BMP4 on Differentiation of Mouse Embryonic Stem Cells to Primordial Germ Cells.

Background: Bone morphogenetic protein 4 (BMP4) has a significant role in primordial germ cells (PGCs) differentiation from mouse embryonic stem cell (mESC). The aim of this study is to determine the best concentration of BMP4 at a time of two days on differentiation PGCs from mESC.

Materials And Methods: To differentiate PGCs, embryoid bodies (EBs) from mESCs were cultured in concentrations of 0, 5 and 10 ng/ml BMP4 for two days.

Analysis of apoptosis and expression of genes related to apoptosis in cultures of follicles derived from vitrified and non-vitrified ovaries.

The aim of this study was to evaluate the incidence of apoptosis after in vitro culture of isolated follicles derived from vitrified and non-vitrified ovaries. Mouse ovaries were vitrified and their pre-antral follicles were mechanically isolated and cultured for 10 days. Growth and survival rates of the follicles were assessed during the culture period and the ultrastructure of the follicles was studied.

The effects of N-acetylcysteine on the expression of matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2 in hepatic fibrosis in bile duct ligated rats.

Aim: N-acetylcysteine can inhibit the formation of intracellular reactive oxygen intermediates. Cellular redox state plays a role in regulating the secretion of matrix metalloproteinase-2. We investigated the effects of N-acetylcysteine on the expression of matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2.

Detection of four beta-thalassemia point mutations in Iranians using a PCR-ELISA genotyping system.

Development of molecular techniques with analytical capability of mutation detection can realize the medical diagnosis of diseases and improve people's health. beta-Thalassemia is one of the most prevalent genetic disorders in Iran and using a simple and rapid test in laboratories for the mass screening and prenatal diagnosis is essential. Here, we described a simple method for rapid detection of four common beta-thalassemia point mutations in Iranians (IVS-II-1 (G-->A), IVS-I-5 (G-->C), FSC 8/9 (+G), IVS-I-110 (G-->A)) using a PCR-ELISA genotyping system.

Comparison of gene expression profiles in erythroid-like cells derived from mouse embryonic stem cells differentiated in simple and co-culture systems.

The feeder layer and the presence of specific growth factors are thought to induce the differentiation of embryonic stem cells (ESCs) in culture. The aim of this study was to evaluate the effect of erythropoietin (EPO) on the differentiation of ESCs into erythroid colonies in simple and co-culture systems. Embryoid bodies were dissociated and replated in semisolid medium in simple culture or in a co-culture system with bone-marrow stromal cells (BMSCs), both in the presence or absence of EPO.

Production of anti-digoxigenin antibody HRP conjugate for PCR-ELISA DIG detection system.

There are several methods used to visualize the end product of polymerase chain reactions. One of these methods is an ELISA-based detection system (PCR-ELISA) which is very sensitive and can be used to measure the PCR products quantitatively by a colorimetric method. According to this technique, copies of DNA segments from genomic DNA are amplified by PCR with incorporation of digoxigenin-11-dUTP.

Changes in hepatic cytosolic glutathione S-transferase activity and expression of its class-P during prenatal and postnatal period in rats treated with aflatoxin B1.

The effect of aflatoxin B1 (AFB1) on the expression of glutathione S-transferase-P (GST-P) which is the major isoform of GST in developmental stages has been investigated in rat liver during prenatal and postnatal stages. Following administration of AFB1 (0, 0.5, 1.

Over expression of anti-MUC1 single-domain antibody fragments in the yeast Pichia pastoris.

The methylotrophic yeast Pichia pastoris has become a highly popular expression host system for the recombinant production of a wide variety of proteins, such as antibody fragments. Camelids produce functional antibodies devoid of light chains and constant heavy-chain domain (CH1). The antigen binding fragments of such heavy chain antibodies are therefore comprised in one single domain, the so-called VH of the camelid heavy chain antibody (VHH).

The production and characterization of novel heavy-chain antibodies against the tandem repeat region of MUC1 mucin.

Camelidae are known to produce immunoglobulins (Igs) devoid of light chains and constant heavy-chain domains (CH1). Antigen-specific fragments of these heavy-chain IgGs (VHH) are of great interest in biotechnology applications. This paper describes the first example of successfully raised heavy-chain antibodies in Camelus dromedarius (single-humped camel) and Camelus bactrianus (two-humped camel) against a MUC1 related peptide that is found to be an important epitope expressed in cancerous tissue.