1.   We have made retrovirus particles displaying a functional antibody fragment.

2.   For example, Iraq did not use the traditional method for making small particles.

3.   These particles are made of even smaller subparticles called quarks and gluons.

4.   Those properties were later used to support the successful theory that the particles are made of elementary particles called quarks, Hadley said.

5.   Making any particle in large numbers allows physicists to measure its mass and other characteristics to great precision.