Abstract: Disclosed herein is a crosslinked HPG fluid system using a very low concentration of HPG polymer. The fluid system is able to be used at low HPG concentrations while maintaining stable viscosity for over two hours at elevated temperatures.

Abstract: An in vitro culture medium that can be utilized for culturing mammalian embryos, especially early-stage embryos, is provided. The culture medium comprises about 10-200 nM insulin-like growth factor 2 (IGF2). A method for culturing mammalian embryos in vitro is also provided, which substantially includes culturing an early stage embryo of a mammal using the culture medium. The in vitro culture medium and method can increase the formation rate of blastocysts of mammals, particularly humans, and can also improve the quality of embryos, thereby improving the success rate of assisted reproductive technologies. The culture medium and method are particularly useful in culturing embryo from an aged mammal or a mammal with obesity.