Amniotic fluid: Source of valuable mesenchymal stem cells and alternatively used as cryopreserved solution.

•We obviously found that the human amniotic fluid is able to apply to use as cryogenic solution instead of either high concentration animal serum or modified culture medium. These findings may useful for further clinical application for cell-tissue transplantation to reduce some side effects of transplanting procedures from cryogenic agent and an intensively used animal serum. Our results also demonstrate that the highest percentage of cell viability of the human amniotic fluid-derived mesenchymal stem cells were found after the cells had preserved in the amniotic fluid supplemented with low concentration of dimethyl sulfoxide (DMSO) and fetal bovine serum.•We found that the human amniotic fluid-derived mesenchymal stem cells are capable of retaining their attributes of stem-ness after cryopreserving process through illustrating typical phenotypic morphologies including fibroblastic-like appearance, an ability of cell proliferation and the expression of mesenchymal stem cell biomarkers, CD44, CD73, and CD90, as well as expression of HLA-ABC (MHC-I). Additionally, regarding to chondrogenic inducing procedure, these mesenchymal stem cells are considerably able to differentiate into chondrocyte-like cells by expressing chondrogenic phenotypic genes and proteins as well as exhibiting the intensively staining of cartilage-specific ground substances, sulfated glycosaminoglycans, filling in scaffold pores.•After observing cells’ ultrastructure, these chondrogenic-like cells also display some remarkably organelles required to protein synthesis in the natural cartilage cells, for instance, the enrichment of rough endoplasmic reticulum, intensive free ribosome and considerable number of mitochondria in cell cytoplasm.