Abstract: The subject invention provides a method for analyzing the metabolic activity in cells by improving the retention of a detectable reporter molecule only in intact cells where a particular enzyme is present. In particular, improved retention results from a two part process involving conjugation of haloalkyl-substituted derivatives of a reporter molecule with intracellular cysteine-containing peptides while unblocking the reporter molecule. The method for analyzing metabolic activity of cells involves the use of a substrate having the formXR-REPORTER-BLOCKwherein -BLOCK is a group selected to be removable by action of a specific analyte, to give REPORTER spectral properties different from those of the substrate,-REPORTER- is a molecule that, when no longer bound to BLOCK by a BLOCK-REPORTER bond, has spectral properities different from those of the substrate, andXR-- is a haloalkyl moiety that can covalently react with an intracellular thiol (Z--S--H) to form a thioether conjugate (Z--S--R--).

Abstract: Novel fluorescent precipitating substrates made from a class of fluorophores, generally including quinazolinones (quinazolones), benzimidazoles, benzothiazoles, benzoxazoles, quinolines, indolines, and phenanthridines, having the general formula: ##STR1## where carbon atoms of --C.sup.1 .dbd.C.sup.2 -- are further joined so as to complete a first 5- or 6-membered aromatic ring which may contain at least one of the hetero atoms N, O or S,where carbon atoms of --C.sup.4 --N.dbd.C.sup.3 -- are further joined so as to complete a second 5- or 6-membered aromatic ring that contains at least the nitrogen between C.sup.3 and C.sup.4 and may contain at least one additional hetero atom N, O or S,where the first and second aromatic rings may be joined by a 5- or 6-membered bridging ring that contains at least the C.sup.2 from the first aromatic ring and the C.sup.

Abstract: The claimed invention relates to a substrate for evaluating glycosidic enzymes comprising a resorufin derivative of the general formula: ##STR1## wherein Gly is a carbohydrate bonded to resorufin by a glycosidic linkage; where at least one of substituents R.sub.1, R.sub.2, R.sub.4, R.sub.6, R.sub.8, and R.sub.9 is a lipophilic residue of the formula --L(CH.sub.2).sub.n CH.sub.3, where n is greater than 3 and less than 22, and where L is a methylene --CH.sub.2 --, an amide --NHCO--, a sulfonamide --NHSO.sub.2 --, a carboxamide --CONH--, a carboxylate ester --COO--, a urethane --NHCOO--, a urea --NHCONH--, or a thiourea --NHCSNH--; andwhere the remainder of substituents R.sub.1, R.sub.2, R.sub.4, R.sub.6, R.sub.8, and R.sub.9, which may be the same or different, are hydrogen, halogen, or other lipophilic residues, which may be the same or different, containing from about 1 to about 22 carbon atoms of the formula --L'(CH.sub.2).sub.m CH.sub.3, where m is less than 22, and where L' is a methylene --CH.sub.

Abstract: The claimed invention relates to a substrate for evaluating glycosidic enzymes comprising a fluorescein derivative of the general formula: ##STR1## wherein GlyX is a carbohydrate bonded to fluorescein by a glycosidic linkage;Y, which may be the same as GlyX or different, is an alkyl ether, an ester, or a glycosidically linked carbohydrate;R is a lipophilic residue containing from 1 to 21 carbon atoms; andL links the R residue to fluorescein.A preferred embodiment of the invention is a non-fluorescent substrate specifically hydrolyzable by a glycosidase inside a cell to yield, after greater than about 2 minutes, a fluorescent detection product excitable at between about 460 nm and 550 nm and with fluorescence observable at an emission wavelength longer than the excitation wavelength, which fluorescent detection product is retained inside a viable cell more than about 2 hours at greater than about 15.degree. C. and which is non-toxic to the cell.