Modified skills of trypsin-digested retinal vasculature mount preparation and string vessels observation

Trypsin-digested retinal vasculature mount is a key method to study vascular retinopathy. However, its failure rate and difficulty maintaining the vascular network's integrity limit its wide application. String vessels occur in the vasculature of different tissues in many species. However, the definition and function of string vessels are full of controversy. This study aimed to explore the skills of preparing complete and repeatable retinal vasculature mounts and further understand the string vessel through observation. We found that the integrity of the retinal vascular network was successfully protected by using toothless micro forceps to clamp the internal limiting membrane and using glass rods to lift the vascular network from the water surface. This modification will not waste the hard-won samples. We observed the different states of the string vessels and hypothesized that they might participate in angiogenesis during vascular development or under pathological conditions.