Fluorimetric studies on progesterone-induced [Ca(2+)](i) signalling in mammalian spermatozoa show both the well-characterised [Ca(2+)](i) transient and a subsequent sustained phase. However, the sustained phase is thought to reflect release of the fluorochrome during the acrosome reaction and has not been subject to critical investigation. We have used single-cell imaging of [Ca(2+)](i) to anal...

A simple and sensitive fluorimetric method for determination of antiviral drugs: ribavirin, acyclovir, and amantadine hydrochloride has been developed. The method was based on the oxidation of these drugs by cerium(IV) in presence of perchloric acid and subsequent monitoring the fluorescence of the induced cerium(III) at lambdaexcitation 255 and lambdaemission 355 nm. Different variables affect...

DNA quantification of soils and sediments is useful for the investigation of microbial communities and for the acquisition of their genomes that are exploited for the production of natural products. However, in such samples DNA quantification is impaired by humic acids (HA). Due to its lack of specificity and sensitivity, UV spectrophotometry cannot be applied. Consequently, fluorimetric assays...

A fluorimetric assay, based on the ability of boiled hepatic extracts to support the sulphO-conjugation of harmol, was used to demonstrate and quantify PAdoPS (adenosine 3'-phosphate 5'-sulphatophosphate) present in liver. A stoicheiometric relationship was established between the sulphate conjugate formed and the 'active sulphate' utilized. Guinea-pig, rat, mouse and rabbit livers contain 3.3,...