To create hydrogels decorated with immobilized purified protein, we fabricated BMPA gels as previously described4, and used a gasket system (ArrayIt Microarray Gasket, ArrayIt Corporation, Sunnyvale, CA) to physically isolate regions of the BMPA gel and selectively dose these regions with protein (see Fig. 1B).
Arrayit Blood Cards utilized in ongoing clinical trials:
Red blood cell folate status will be analyzed through dried blood spot samples collected on Arrayit blood cards, which use linear flow chromatography to separate whole blood into erythrocyte and serum. Red blood cell folate values represent a longer-term reduction in folate consumption or increases in folate excretion. Overturn of red blood cells occurs every 4 months, therefore, red blood cell folate status will only be assessed at baseline. The WHO-recommended cutoff of <340 nmol/L will be used to assess low red blood cell folate status.