Keystone Perfusion Services is a proud member of the American Staffing Association (ASA), which promotes legal, ethical and professional practices for the staffing industry. Every member of the American Staffing Association is guided by a rigorous code of ethics. Members receive detailed, practical guidance as well as ongoing education and training in employment law. More than 5,000 staffing professionals have been certified by ASA. Membership in ASA is a hallmark of excellence and high standards in the staffing industry.