Personalized Body Builder Youth T-Shirt. Bio Engineer, body builder text with a strand of DNA is a humorous design for biological engineers. Fun gifts for bioengineers at birthdays, holidays and graduation. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.