BioBrick

A BioBrick is a DNA part built to a shared technical standard so that it can be combined with other parts like a building block. Each part does one defined job, for example switching a gene on, helping ribosomes bind, coding for a protein or ending transcription, and is kept in plasmids grown in E. coli. Tom Knight at MIT proposed the standard in the early 2000s, and parts are catalogued under unique numbers in the Registry of Standard Biological Parts.

In the original standard, every part has a prefix in front carrying sites for the restriction enzymes EcoRI and XbaI, and a suffix behind carrying sites for SpeI and PstI; the part itself must not contain those sites. XbaI and SpeI leave matching sticky ends, so two parts can be cut and ligated together, leaving a short eight-base scar, and the joined product is again a BioBrick with the same prefix and suffix. That property lets designers build larger devices one step at a time.

Students meet BioBricks through the iGEM competition, where teams design and share new parts. Because the original scar shifts the reading frame, later standards were written to allow protein fusions.