Lindsey Rucker Hugh Hobbs Ahson Saeed School of

Lindsey Rucker, Hugh Hobbs, Ahson Saeed School of Chemical, Biological, and Environmental Engineering Traditional Method 1. 2 1 1 0. 8 JPD JWD 0. 6 0. 4 0. 2 0 0 Solution HP applies their thermal inkjet printing technology to simplify the drug titration method. One HP consumable print head is loaded, which is capable of dispensing over a range of 15 p. L to 1 µL. This leads to reduced labor costs and time requirements, and increased precision. HP Direct Titration Method • Simplifies drug titration method • Leads to reduced labor costs • Reduction in time 10 20 16 of the nozzles depicted at the left are present on the printer heat used in the instrument. r=fluid density α = acceleration due to gravity interface A significant change in counts is caused by the solution not being fully mixed. Once the fluorescence signal, or counts, reaches a steady level, the conclusion can be made that mixing has occurred. This has been determined to be the best method to quantify mixing using kinetic data. Vessel Standard water cup Chart Title 1. 2 1 0. 8 0. 6 0. 4 0. 2 0 96 well plate 20 Time (s) 40 60 384 well plate 45 mm 3. 5 mm Theoretically Mix 1200 270 1. 7 Yes 1 u. L FBLR 1. 5 mm 0. 07 2 1. 8 1. 6 1. 4 0. 06 0. 05 0. 04 0. 03 1 n. L FB 2 mm 1 n. L FB 0. 5 mm 1 n. L FBLR 1. 5 mm 0. 02 1. 2 0. 01 1 0 0 20 Time (s) 40 60 0 20 Time (s) 40 • The team recommends to use JPD in the FBLR direction for larger dispense volumes. JPD is also the optimal mixing method for small volumes, however, stage direction requires further testing. • It is recommended to further investigate the jitter time and amplitude for both large and small dispense volumes. Yes Acknowledgements 800 600 400 200 1. 9 mm 0. 08 1000 Bond Number Quantitative Method Bond Radius Number 1 u. L FB 0. 5 mm Counts( 1 E 6) Counts (1 E 6) Bond Number: A ratio of the body forces to the surface tension forces. A bond number less than 1 indicates that the surface tension forces are dominating the body forces. L = radius of capillary tube g= surface tension of the 0 Immediately after dispense 60 0. 09 1 u. L FB 2 mm 2. 2 Qualitative Method “Jittering”: oscillation of the well plate using the stage to induce shear between the deposited fluid, and fluid already in well. The stage can oscillate in the front to back direction (FB) or dual axis (FBLR). Counts( 1 E 6) Jitte r No Cell Death Time(s) 40 B 2. 4 • DMSO penetrating in single point • Cell death caused by high concentration at points of penetration. Immediatel 5 1 minute y after seconds after dispense e 20 Proposal Jittering Method No Jitter 0 60 • Plot A displays results for 50 n. L dispense volume, and plot B displays results for 200 n. L dispense volumes. Is Mixing Achievable? Cell death 50 • JPD has been determined to be the optimal mixing method for both large and small dispense volumes, based on the slopes in the data plotted above. Traditional Method Challenge: Why Mixing Is Necessary Time (s) 40 • Two jittering methods were tested for mixing results: Jitter- while- dispense (JWD) and Jitterpost- dispense (JPD). Improvements Over the Old Method HP Method 30 JWD A Hewlett Packard Titration Tool and Print Head In essence thermal inkjet technology consists of a resister and a fluid reservoir. The resister is positioned directly under (above) the filling reservoir. The resistor rapidly heats the fluid forming a bubble which pushes a drop of ink out of the nozzle. 0 JPD 0. 6 0. 4 Thermal Inkjet and Titration Tool Thermal Inkjet Technology Counts( 1 E 6) Drug discovery involves a titration process in which the effects of different concentrations of potential drug compounds are analyzed. Current methods of analysis involve steps which are labor intensive, error prone and, more importantly time consuming. Results Counts( 1 E 6) Problem Thermal Inkjet Dispense for Pharmaceutical Research 0. 5 No 0 0 Radius (m) The Engineering Team would like to thank: • Hewlett Packard • Kenneth Ward • Heather Paris • Ken Duda • Michael J Day • Philip H Harding 60