Reference

Reactions of seven basic fluorochromes with unfixed cells obtained from the salivary glands of the dipteran fly Megaselia scalaris Loew (Phoridae)

Reactions of seven basic fluorochromes with unfixed cells obtained from the salivary glands of the dipteran fly Megaselia scalaris Loew (Phoridae). Curtis, S. K.; Cowden, R. R.; Benner, D. B. (Quillen-Dishner Coll. Med., East Tennessee State Univ., Johnson City, TN 37614-0002, USA). Histochemistry, 85(6), 475-81 (English) 1986. CODEN: HCMYAL. ISSN: 0301-5564. DOCUMENT TYPE: Journal CA Section: 9 (Biochemical Methods) Section cross-reference(s): 12 Seven basic fluorochromes with varying specificities were used to stain the large squamous epithelial cells isolated from the larval salivary glands of M. scalaris. Although the EDTA-based method selected for isolating the cells produced permeabilization and a loss of viability of the cells, consistent results were obtained with the various fluorochromes. The classical pattern of green nuclear and red cytoplasmic fluorescence obsd. in cells stained with Acridine orange could be changed to green cytoplasmic and red nuclear fluorescence by pretreatment with RNase. The predominantly cytoplasmic and nucleolar fluorescence obtained with Pyronine Y could be changed to mainly nuclear fluorescence by RNase pretreatment. 12768-82-0 and 92-32-0 are also in the experiment. The other 5 fluorochromes tested were not affected appreciably by extn. with RNase. Quinacrine mustard, dicarbocyanine, and Rhodamine 123 produced primarily cytoplasmic and nucleolar fluorescence, whereas Nile red revealed mainly cytoplasmic lipid droplets. Phosphine 3R initially stained lipid droplets but very rapidly redistributed throughout the cytoplasm and nucleus. Because of their large size, flatness, and content of histochem. demonstrable components, the cells of Megaselia are esp. appropriate for use as optical objects or controls in various studies. New methods of isolating the cells, however, will be needed to prevent permeabilization and loss of viability of the cells. .

Predicting the behavior and selectivity of fluorescent probes for lysosomes and related structures by means of structure-activity models

Predicting the behavior and selectivity of fluorescent probes for lysosomes and related structures by means of structure-activity models. Rashid, Fiza; Horobin, Richard W.; Williams, M. A.In this study， 1328-03-6 and 12768-82-0 are also used. (Dep. Biomed. Sci., Univ. Sheffield, Sheffield S10 2TN, UK). Histochem. J., 23(10), 450-9 (English) 1991. CODEN: HISJAE. ISSN: 0018-2214. DOCUMENT TYPE: Journal CA Section: 9 (Biochemical Methods) Cultured rat fibroblasts were exposed to 50 fluorescent probes of varied physicochem. characteristics. Probe concns., fluorochrome excitation wavelength and period of illumination, and cell probe contact time were varied. Structure-activity relations defining a no. of classes of fluorescent probes for lysosomes and related processes and compartments were demonstrated. Numerical specifications are now available for several familiar classes of probes: (1) acidotropic weak bases, used as markers for low pH compartments; (2) markers of adsorptive pinocytosis, involving nonspecific protein binding; (3) markers for fluid phase pinocytosis; and (4) viability stains involving intralysosomal enzymic activity. Two novel classes of probes also were specified numerically: (1) acid-pptd. weak acids, as markers for low-pH compartments and (2) lipid-binding markers of adsorptive pinocytosis. Overall, these structure-activity models provide a tool for predicting whether or not compds. enter cells; and whether they accumulate in lysosomes and related compartments. Pathways of entry also are predicted. This tool should permit design and selection of improved probes and provide a better understanding of existing reagents. Moreover, these models are expected to be applicable to interactions between any nonpolymeric xenobiotic with lysosomes and related compartments. .