Ribonucleic acids (RNAs) are considered as effective and minimally invasive biomarkers for disease diagnosis and prognosis due to their critical role in the regulation of different cellular processes. Over the past several years, the rapid progress in RNA biomarker research has resulted in the development of a large number of high‐performance RNA‐detection methods. Most of these methods are based on molecular‐biology techniques such as quantitative reverse transcription polymerase chain reaction (RT‐qPCR), microarrays, and RNA sequencing. In recent years, considerable attention has also been dedicated to developing RNA biosensors, exploiting micro‐ and nanofabrication technologies, and various readout strategies, including electrochemical and optical transducers. Here, the recent developments of RNA biosensors are concisely reviewed with a special emphasis on electrochemical‐detection approaches. The following points are also highlighted: i) all the types of clinically relevant RNAs (mRNAs, miRNAs, lncRNAs) and their diagnostic and prognostic potential in cancer are outlined, ii) major challenges associated with current techniques are identified, followed by a critical analysis of how these challenges have been addressed by different biosensing approaches, and iii) the current requirements that still need to be met for effective screening of RNA biomarkers in both research and clinical settings.

Antibiotic-free broiler meat production is becoming increasingly popular worldwide due to consumer perception that it is superior to conventional broiler meat. Globally, broiler farming impacts the income generation of low-income households, helping to alleviate poverty and secure food in the countryside and in semi-municipal societies. For decades, antibiotics have been utilized in the poultry industry to prevent and treat diseases and promote growth. This practice contributes to the development of drug-resistant bacteria in livestock, including poultry, and humans through the food chain, posing a global public health threat. Additionally, consumer demand for antibiotic-free broiler meat is increasing. However, there are many challenges that need to be overcome by adopting suitable strategies to produce antibiotic-free broiler meat with regards to food safety and chicken welfare issues. Herein, we focus on the importance and current scenario of antibiotic use, prospects, and challenges in the production of sustainable antibiotic-free broiler meat, emphasizing broiler farming in the context of Bangladesh. Moreover, we also discuss the need for and challenges of antibiotic alternatives and provide a future outlook for antibiotic-free broiler meat production.

We report a new method for the detection of regional DNA methylation using basedependent affinity interaction (i.e., adsoption) of DNA with graphene. Due to the strongest adsorption affinity of guanine bases towards graphene, bisulfite-treated guanine-enriched methylated DNA leads to a larger amount of the adsorbed DNA on the graphene-modified 2 electrodes in comparison to the adenine-enriched unmethylated DNA. The level of the methylation is quantified by monitoring the differential pulse voltammetric current as a function of the adsorbed DNA. The assay is sensitive to distinguish methylated and unmethylated DNA sequences at single CpG resolution by differentiating changes in DNA methylation as low as 5%. Furthermore, this method has been used to detect methylation levels in a collection of DNA samples taken from oesophageal cancer tissues.

The present research work was carried out to isolate and identify Newcastle disease virus (NDV) by using haemagglutination inhibition (HI) test and reverse transcription-polymerase chain reaction (RT-PCR) assay. A total of 160 clinical (blood, tracheal and cloacal swabs) and post-mortem (brain, lung, colon and spleen) samples were collected from chickens of two field outbreaks of Newcastle disease (ND) in 2006, one in a broiler (Cobb-500) farm of Mymensingh district and other one in a layer (Sonali) farm of Gazipur district. All the samples were inoculated onto 10-day-old embryonated chicken eggs through allantoic sac route and in the chicken embryo fibroblasts (CEFs) cell culture. The allantoic fluid (AF) of the dead embryos and the infected culture fluid (ICF) of the CEF were harvested at 48 and 96 hours of post-infection, respectively. The HI and RT-PCR were employed to detect NDV in tissue homogenates of all the clinical and post-mortem samples as well as laboratory samples (AF and ICF). Among the clinical samples, virus isolation rate was found higher from tracheal swab (90%) compared to those of cloacal swab (85%) and serum (65%). On the other hand, among the four different types of post-mortem samples, virus isolation rate was found higher in spleen (100%) compared to those of lungs (80%), colon (60%), and brain (80%) samples. In CEF cell culture system, the rate of virus isolation from all the aforesaid samples was found 100% with the exception of serum samples. The isolation rate of NDV was higher in CEF culture system (93.8%) compared to that of avian embryos (80%). Among the clinical and post-mortem samples, inoculum of only cloacal swab and colon showed HA and HI activities. The anti-NDV hyperimmune serum revealed complete inhibition of the 4 haemagglutination unit of each isolate of viruses isolated from broiler and layer chickens present in the laboratory samples (AF and ICF). The NDV specific primers used in the direct RT-PCR for genome detection of NDV showed equal sensitivity and specificity with the RNA extracted from the clinical, post-mortem and laboratory samples (AF and ICF) as with the genomic RNA of reference NDV. Higher rate of detection of NDV was recorded with RT-PCR assay than HI test. Therefore, the molecular method (RT-PCR) can be introduced for rapid and confirmatory detection of NDV from any form of outbreak of ND in the field level of Bangladesh.