Provided is a whole-cell biosensor system with robust biocontainment for field deployment and a strong visual reporter for readouts in the deployed environment. The engineered biosensors in an encapsulated and deployable system (eBEADS) demonstrate a portable, no power living sensor for detection of environmental pollutants, e.g., 2-phenylphenol (2-PP). The whole-cell biosensor system uses bacteria engineered to detect an analyte and generate a visual colorimetric output upon being contacted with the analyte. Advantageously, the analyte is detectable with the naked eye and the whole-cell biosensor system enables analyte detection without electronics.

Methods of determining whether a toxicant is present in a consumable product, which comprise contacting a teleost embryo with an extract from a sample of the consumable product and determining whether the extract exerts a toxicity effect on the embryo.

An object is to provide a technique for detecting a nitro compound. The object is achieved by a nitro compound detection element formed from a specific type of an insect olfactory receptor or from an insect olfactory receptor having a specific mutation introduced.

A cell composition composed of spermatogonial stem cells, Sertoli cells, Leydig cells and optionally peritubular cells, is provided, as is a culture composition, artificial testicular construct, hydrogel composition, and device containing the same. A method for using the device as a physiologically relevant in vitro model of human testicular function to screen compounds for pharmacological or toxicological activity is also provided.

UO.sub.2F.sub.2 biosensors, and related U-sensing and/or F-sensing genetic molecular components, genetic circuits, compositions, methods and systems are described, which in several embodiments can be used to detect and/or neutralize uranium and in particular bioavailable UO.sub.2F.sub.2.

Systems and methods relate to transgenic organisms and their use as biosensors are described. In some embodiments, the systems and methods include a first population of transgenic organisms that includes a first constitutively expressed reporter gene, and a first transgene that includes a first inducible promoter from a response pathway gene, wherein the first inducible promoter is coupled to a first reporter gene. Other embodiments are described.

UO.sub.2F.sub.2 biosensors, and related U-sensing and/or F-sensing genetic molecular components, genetic circuits, compositions, methods and systems are described, which in several embodiments can be used to detect and/or neutralize uranium and in particular bioavailable UO.sub.2F.sub.2.

Provided is a method for detecting ammonia nitrogen content by using a nitrification biological reaction. In the present disclosure, the nitrifying microorganisms have high specificity for ammonia nitrogen, a metabolism and oxygen consumption capacity closely related to the ammonia nitrogen concentration, high accuracy and high sensitivity of ammonia nitrogen detection, and are not easily disturbed by water body chromaticity, suspended matters, and the like. In addition, the activity of the nitrification microorganism membrane reactor can be kept stable for a long term, and the stability of a sensor is good for long-term use. In the present disclosure, with a mono-component or multi-component solution containing inorganic nitrogen and inorganic carbon as a nitrification nutrient solution, a nitrification microorganism membrane with strong adaptability to the environment, a stable structure, a high selectivity for ammonia nitrogen, and an ability of efficiently degrading ammonia nitrogen can be obtained.

Described herein are DNA primer sequences designed for the determination of gene or transcript information from Anuran species, and which may be used in studies for developmental and/or toxicity testing and for environmental toxicology or ecological assessment. Also described herein is a rapid, sensitive, high-throughput assay useful for supporting potential risk assessment across vertebrate clades, and that is also useful for evaluation of complex contaminant mixtures.

UO.sub.2F.sub.2 biosensors, and related U-sensing and/or F-sensing genetic molecular components, genetic circuits, compositions, methods and systems are described, which in several embodiments can be used to detect and/or neutralize uranium and in particular bioavailable UO.sub.2F.sub.2.