One of the first things the students do is prepare a few batches of chemi-competent E. coli. The cells are stored in the minus 80 freezer and later retrieved when needed for testing, or ultimately the gene cloning projects. With the -80, students quickly learn the importance of documentation. One needs to know exactly where one's sample is, and this information should be in one's lab notebook. It is not permissible to stand in front of the -80 and thaw everything out while looking for a sample.