A simple assay for the study of solubilized acetylcholine receptors

Detergent-solubilized acetylcholine receptors from the electric organs of Electrophorus electricus and Torpedo californica are rapidly, quantitatively and specifically assayed by exposure to ¹²⁵I-α-bungarotoxin and subsequent adsorption onto DEAE-cellulose paper disks.     

A simple assay to study social behavior in Drosophila: measurement of social space within a group

We have established a new simple behavioral paradigm in Drosophila melanogaster to determine how genes and the environment influence the behavior of flies within a social group. Specifically, we measure social space as the distance between two flies. The majority of Canton-s flies, regardless of their gender, are within two body lengths from each other. Their social experience affects this behavior, with social isolation reducing and mating enhancing social space respectively, in both males and females. Unlike several other social behaviors in the fly, including the formation of social groups themselves (a well-described behavior), social space does not require the perception of the previously identified aggregation pheromone cis-vaccenyl acetate. Conversely, performance of the assay in darkness or mutations in the eye pigmentation gene white increased social space. Our results establish a new assay for the genetic dissection of a fundamental mode of social interaction.     

Morphological and biochemical adaptations to feeding in some herbivorous gastropods

Feeding range and modes as well as morphological and biochemical adaptations to feeding are analyzed in herbivorous mollusks. The content of hemoglobin in radular tissues and weight properties of the radula are evaluated for different modes of feeding.Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 1, 2005, pp. 69–77.Original Russian Text Copyright © 2005 by Alyakrinskaya.     

A simple assay procedure for beta-D-mannanase.

A simple assay procedure for beta-D-mannanase enzyme has been developed which employs carob D-galacto-D-mannan dyed with Remazolbrilliant Blue. Additionally, the procedure is quantitative, relatively sensitive, and highly specific for beta-D-mannanase enzyme. It can be readily used for the determination of beta-D-mannanase activity in crude enzyme preparations and column-chromatography eluates.     

A simple and sensitive assay for dopamine-beta-hydroxylase

A simple, rapid, and highly sensitive radiochemical assay for measuring the activity of dopamine-β-hydroxylase in tissues and serum is described. Enzyme activity is detected by converting [1-¹⁴C]tyramine to [1-¹⁴C]octopamine which is then subjected to periodate cleavage to form [¹⁴C]form-amide. This radiolabeled product is oxidized to ¹⁴CO₂ by addition of permanganate and the ¹⁴CO₂ is trapped and counted. The assay is simple and sensitive, it can linearly detect enzyme in all tissues with a wide range of activity, it uses maximal concentration of substrate, and it requires the addition of only one concentration of EMI to block endogenous inhibitor(s) in different tissues or enzyme concentrations.     

A simple radiochemical assay for prostaglandin synthetase

A simple radiochemical procedure for prostaglandin synthetase is described, in which incubation mixtures are applied to small disposable columns of Bio-Sil A (silica gel) resin and eluted with two different solvent mixtures to achieve a separation of unmetabolized substrates from prostaglandin products.