Transparent soft PDMS eggshell
In vivo 3D fluorescent image remains a technological barrier for biologists and clinical scientists although green fluorescent protein (GFP) imaging has long been performed rather well at cellular level. Meanwhile, robust enough portable devices are also challenging lab-on-a-chip advocators who wish their designs to be nurtured by the end users. This work is dedicated to propose a conceptually innovated transparent soft PDMS avian eggshell to directly tackle the above two goals. Here, an “egg-on-a-chip” scheme is originally developed and demonstrated by a newly developed PDMS “soft” process method. Unlike its ancestor-the conventional “lab-on-a-chip” (LOC) which is basically chemically based, the current “egg-on-a-chip”, intrinsically inherited with biological natures, opens a way to integrate biological parts or whole system in a miniature sized device. Such biomimics system contains much condensed environmental evolutional tensor inside than those of the existing LOC compacted with artificial components which however are quite difficult to incorporate various life factors inside. Owning unique advantages, a series of transparent PDMS whole “eggshells” have been fabricated and applied to culture avian embryos up to 17.5 days and chimeric eggshells were engineered on normal eggs. In addition, X-stage embryos were successfully initiated in such system and pre-chorioallantoic membrane was observed. Further, limitation of the present process was interpreted and potential approach to improve it was suggested. With both high optical transparency and engineering subtlety fully integrated together, the present method not only provides an ideal transparent imaging platform for studying functional embryo development including life mystery, but also promises a future strategy for “lab-on-an-egg” technology which may be important in a wide variety of either fundamental or practical areas.