A simple method for making reproducible fibre loops for protein cryocrystallography

A practical, step-by-step description of the construction of loops for protein cryocrystallography using pulled-out micro-injection capillaries is described. The advantages of this method are the high reproducibility of the loops, the ease of adjustment of the loop diameter and the formation of thin films owing to the narrow base of the loop. During assembly, the loop does not make contact with either glue or cement.