LabBench Activity

Analysis of Results II

Each fragment of DNA is a particular number of nucleotides, or base pairs, long. When researchers want to determine the size of DNA fragments produced with particular restriction enzymes, they run the unknown DNA alongside DNA with known fragment sizes. The known DNA acts as a marker. In your laboratory, the DNA that has been cut with HindIII is the marker; you will use it to help you determine the fragment sizes in the EcoRI digest. On the next pages we go through the procedure using HindIII and two generalized DNA samples.