Newborn screening is currently performed by collecting dried bloodspots from infants and then sending them to a lab for analysis. Lysosomal storage diseases alone number greater than 40 and there is an increasing necessity to screen for a number of disease conditions for which therapies are becoming available. Tandem mass spectrometry is an excellent multiplex detection technology widely utilized in newborn screening, but when applied to enzyme assays it is very expensive, time consuming, labor intensive, and more importantly the multiplexing power of mass spectrometry is not leveraged because each assay has to be performed individually. There is a need for an inexpensive, rapid, automated, and scalable technology for performing newborn screening assays that a mass spectrometer is not well-suited to perform. A digital microfluidic system for performing enzymatic assays in newborn screening will enable walkaway automation and multiplex several assays very inexpensively. Based on Advanced Liquid Logic's successful demonstration of digital microfluidic manipulation of nanoliter-sized droplets of enzymatic reagents and sample for dispensing from on-chip reservoirs, high speed transport, mixing, splitting and dilution, and absorbance, fluorescence, and luminescence detection of the assays, a disposable lab-on-a- chip will be developed. In phase I, we have successfully demonstrated a multiplex fluorescence enzymatic assay on a digital microfluidic cartridge to setup screening for Pompe, Fabry, and Hurler disorders on dried blood spot samples. Phase II work will focus on increasing the throughput of the cartridge to screen for 6 lysosomal storage disorders for which therapies exist including Pompe, Fabry, Hurler, Hunter, Gaucher, and Maroteaux-Lamy, on 96 dried blood spot samples yielding a total of 576 enzymatic assays on a single cartridge. Also, a pilot screening study will be performed in collaboration with Duke University and North Carolina State Lab of Public Health, which would involve screening about 10,000 dried blood spots on the digital microfluidic platform.
Newborn screening is performed on every infant born in the US and there is a growing interest in increasing the number of conditions screened for. In this project, a digital microfluidic platform will be developed to screen for many treatable conditions simultaneously using much lesser volume of blood from an infant. It would be greatly useful in identifying treatable diseases earlier.
| Sista, Ramakrishna S; Wang, Tong; Wu, Ning et al. (2013) Rapid assays for Gaucher and Hurler diseases in dried blood spots using digital microfluidics. Mol Genet Metab 109:218-20 |
| Sista, Ramakrishna S; Wang, Tong; Wu, Ning et al. (2013) Multiplex newborn screening for Pompe, Fabry, Hunter, Gaucher, and Hurler diseases using a digital microfluidic platform. Clin Chim Acta 424:12-8 |
| Graham, Carrie; Sista, Ramakrishna S; Kleinert, Jairus et al. (2013) Novel application of digital microfluidics for the detection of biotinidase deficiency in newborns. Clin Biochem 46:1889-91 |
| Sista, Ramakrishna S; Eckhardt, Allen E; Wang, Tong et al. (2011) Digital microfluidic platform for multiplexing enzyme assays: implications for lysosomal storage disease screening in newborns. Clin Chem 57:1444-51 |
| Millington, David S; Sista, Ramakrishna; Eckhardt, Allen et al. (2010) Digital microfluidics: a future technology in the newborn screening laboratory? Semin Perinatol 34:163-9 |
