Carlsbad-based Invitrogen, a provider of services to the pharmaceutical and biotech market, said Friday that it has made a minority invevstment in Q Therapeutics, a biotechnology firm focused on treatments for central nervous system diseases. Financial terms of the investment were not disclosed. Q Therapeutics is based in Salt Lake City, Utah. Invitrogen is a $1.3B life science technologies with over 4,700 employees.