“…In consideration of the aforementioned reasons the development of a facile, rapid and cost effective method for the L-CySH determination within embryo cell culture media and other biological samples for clinical applications is significant [2]. A vast number of analytical methods have been employed with this purpose, including both high performance liquid chromatography and capillary electrophoresis coupled to fluorescence [13,14], UV-Vis spectroscopy [15,16], mass spectrometry [17,18] and electrochemical detectors [19,20], as well as methodologies based on fluorescence microscopy [21] and chemiluminescence [7,22]. Nonetheless, although those analytical methods are sensitive, selective and accurate, they are time-consuming, require sample preparation and handling, and are unfeasible for routine analysis [5,6,23].…”