The phrase "study at sterile" can be rephrased using various synonyms to convey the same meaning. For example, "conduct research in a controlled environment," "examine under laboratory conditions," or "analyze in a germ-free setting." These synonyms all communicate the idea that research or study is taking place in a space that is free from contamination or outside influence, allowing for accurate and precise observations to be made. Other alternatives could include "investigate in a hygienic location," "explore in a sanitized room," or "scrutinize in a disinfected setting." Regardless of the synonym used, the central idea remains the same, that research is being carried out in a sterile and controlled environment.