Static and dynamic acute cytotoxicity assays on microfluidic devices.
Static and dynamic acute toxicity assays of cells were performed on microfluidic devices where materials were hydraulically transported. Static assays were performed by incubating cells with an agent in a microchip reservoir and optically interrogating the cells after hydrodynamic focusing at a cross intersection. Dynamic assays were performed on a microchip with a 25-cm-long spiral channel where the cells were mixed with an agent and optically monitored 0.1, 12, and 22 cm from the point of mixing. The incubation time was determined by the time needed for cells to transit from the mixing location to the point of detection. Cell viability was determined using the ratio of fluorescence signals from membrane permeant (calcein) and membrane impermeant (propidium iodide) stains. The model system used in this study was the viability of Jurkat cells in the presence of the agent Triton X-100). An average LC50 value of 138 microM for Triton X-100 was obtained for an incubation period of 7-12 min using the static assay. LC50 values obtained with the dynamic assay for 25- and 47-s incubation times were 290 and 250 microM Triton X-100, respectively. Higher LC50 values for the dynamic assay were expected due to the shorter incubation times.
Poulsen
Claus R
CR
Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Culbertson
Christopher T
CT
Jacobson
Stephen C
SC
Ramsey
J Michael
JM
D002470:Cell Survival / Q000187:drug effects; D005452:Fluoresceins / Q000032:analysis; D005453:Fluorescence; D006801:Humans; D019169:Jurkat Cells; D007928:Lethal Dose 50; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D017830:Octoxynol / Q000494:pharmacology; D011419:Propidium / Q000032:analysis; D023382:Toxicity Tests, Acute / Q000295:instrumentation*
D005452:Fluoresceins; D011419:Propidium; D017830:Octoxynol; C007740:fluorexon