The PIT method: an automated in vitro technique for drug toxicity testing

Abstract

An automated in vitro technique for drug toxicity testing is described. Human tumor cells were cultured for 2 days in 96-well microtiter plates before the addition of serial dilutions of drugs. At day 5 the cultures were terminated by the addition of a solution containing propidium iodide, ink and triton X-100 (PIT). Triton X-100 lysed all cells, which were subsequently stained by the DNA specific fluorescing propidium iodide. The ink effectively quenched all background fluorescence. The plates were read on a computer controlled automated microscope with a photomultiplier. The results showed a linear relationship between cell number and fluorescence intensity. Reproducible dose-response curves were obtained for 6 drugs tested. A computer program calculated ID50 values, making use of adequate growth and no-growth controls.

Crystal structure and in vitro antitumour activity of dibutylbis(5‐chloro‐2‐hydroxybenzoato)tin(IV)

“…76; a-CH2), 6.95 (d, 9; 3-H), 7.43 (dd, 9,3; 4-H), 7.45 (d, 3; 6-H) and 10.5 ppm (bs; OH). The NMR data were recorded in CDCI, solution (internal TMS) and were assigned by use of incremental rules for aromatic substitution' together with I3C DEPT spectra in which resonances from quaternary C atoms are suppressed; the calculated values of the chemical shifts of C-1 to C-6 are given in parentheses: 6 13.6 (CH,), The analysis of variance showed no special features and the maximum-residual in the final difference map was 0.56 e A-'.…”

Synthesis, Spectroscopic Characterization and Antitumour Activity of Diorganotin(IV) Derivatives of N‐Substituted Ortho‐Aminobenzoic Acid

“…experimental data d: [7] dd: [7,7] dd: [7,7] [7,7] dd: [7,7] d: [7] rn rn 4 8.711 7.539 7.096 7.9 1.4-1.7 1.3-1.4 d: [7] dd: [7,7] dd: [7,7] Two I3C signals from tin methyl groups are again observed for compound 5 . Note that the tin-proton coupling constants are quite different for these two methyl groups which is expected because they are linked to tin atoms having different coordinations.…”

“…Drug activity was determined using an automated in vifro technique described previously (7). The organotin compound is dissolved in DMSO and this solution is poured onto such an amount of water that the final solution contains less than 0.3% DMSO.…”

Sodium azide is less suitable as a positive control of drug-induced lethality for in vitro clonogenic assays

“…The influence of sodium azide on neighbouring cultures was also studied using the recently introduced automated fluorescence technique for drug cytotoxicity screening (5). Briefly, 104 WiDr cells in 0.1 ml of Dulbecco's medium supplemented with 10% fetal calf serum were put into the wells of a 96-well microtiter plate (Falcon, type 3070) and incubated at 37~ in a humidified atmosphere of 10% CO 2 in air.…”