Addressing Punch Conservation with Digital Microfluidics

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Originally posted in APHL’s Lab Matters Spring 2019 by Candice Brannen, PhD, Senior Director of Laboratory Products

As public health newborn screening (NBS) programs expand to test for more conditions, we’ve heard that there is growing concern that the standard volume of dried blood spots (DBSs) collected from each newborn may not be sufficient to perform all screening tests. The current standard newborn card contains five DBSs. In order to accommodate additional tests, NBS programs can change the standard practice for collection of more blood spots or require new tests to utilize technology that conserves existing sample volume.

Changing the standard practice may not be a good option. By requiring collection of additional blood spots, the risk of inadequate and unsatisfactory samples may increase. The increased risk may be avoided by adopting technology that enables more tests to be performed from the current standard 3.2 mm punch of a DBS.

Digital microfluidics fluorometry (DMF) technology enables the precise manipulation of discrete droplets and can support multiple assay formats including enzymatic biochemical reactions, immunoassays, and molecular analyses. This technology is uniquely positioned to address this issue of punch conservation.

To perform tests from a standard 3.2mm DBS punch, 100 uL of solution is added to extract assay analytes into solution. Since each DMF assay only requires 0.1 uL of DBS extract, nearly 1,000 discrete reactions could be performed using the DBS extract from one punch. In addition, standard cartridges can be readily modified to accept more samples or more assays per cartridge. With DMF, the miniaturized assay format conserves sample usage, reduces reagent costs and minimizes the installation footprint.

Sample volume doesn’t have to limit the expansion of NBS. DMF technology, while not the only solution, is a great start.

Newborn screening punch conservation with digital microfluidics

Credit: Baebies. This graphic not was not published in Lab Matters.

Baebies looks forward to continued partnerships with public health NBS programs to provide testing as we carry out our mission—to save lives and make lives better for children everywhere.

Baebies is a gold level sustaining member of APHL.

Baebies’ DMF technology is protected by more than a hundred patents and is utilized by SEEKER®, the first FDA-cleared test for lysosomal storage disorders (LSDs)–Pompe, MPS I, Gaucher, and Fabry. SEEKER® is currently used for LSD NBS in six US states and in Qatar. Since DMF technology supports a variety of assay formats, Baebies is actively expanding our assay pipeline in order to offer more tests.

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Read the full digital issue of APHL Lab Matters Spring 2019 including feature story “The Promise and Challenge of Newborn Screening in 2019”.