line evaluation this cell line produced an average current amplitude of 650 pa which was reduced from the 800 pa observed in the cell line evaluation phase of this study current stability was high and approached 90 while replicates used in these experiments may have increased our screening time sufficient data was produced within the screening time designated with the new ionworks quattro a technology incorporating population patch clamp u2122 technology increased number of recording holes in the patchplate well the redundancy practiced here will be eliminated at 30 u03bcm 160 compounds blocked herg current gt 50 the 160 compounds so identified were re screened using an eight point concentration response with the ionworks ht system five drugs were screened per run along with positive haloperidol and negative pbs with 0 1 dmso controls the average haloperidol ic 50 generated with ionworks ht was 0 74 0 36 u03bcm from 31 experiments historic standard patch clamp data for haloperidol collected at 37 u00b0 c with a different cell line under different experimental conditions varied from 0 025 to 0 12 u03bcm the 160 compound screen took five days to complete with an individual concentration tested in 16 patchplate wells as previously discussed the redundancy in compound testing was to ensure a large number of data points were produced to build confidence in the data set one data set originating from one project was selected for further evaluation since all compounds in this subset had been tested by standard patch clamp the historic patch clamp data and ionworks ht data were positively correlated spearman r 0 53 p lt 0 004 compounds that yielded a herg.