EcoRI can exhibit non site-specific cutting, known as star activity, depending on the conditions present in the reaction.

Star activity can happen because of presence of Mg, as is seen in HindIII, for example.

Alcohol suppresses StAR activity.

For example, for restriction endonucleases incorrect activity (star activity) is often lethal for the organism, but a small amount allows new functions to evolve against new pathogens.

Members discussed STAR, which is based on NASA curriculum, and brought "toys" to provide a hands-on demo of some of STAR activities.

Conditions that can induce star activity when using EcoRI include low salt concentration, high glycerol concentration, excessive amounts of enzyme present in the reaction, high pH and contamination with certain organic solvents.

Star activity is a relaxation or alteration of the specificity of restriction enzyme mediated cleavage of DNA that can occur under reaction conditions that differ significantly from those optimum for the enzyme.

TVLM513-46546 is an ultracool red dwarf in the constellation Boötes, exhibiting a flare star activity and all the same varying semi-regularly due to dissimilarly bright hemispheres and a rotation period of about two days.

The latter condition is of particular practical interest, since commercial restriction enzymes are usually supplied in a buffer containing a substantial amount of glycerol (50% v/v is typical), meaning insufficient dilution of the enzyme solution can cause star activity; this problem most often arises during double or multiple digests.