Is DNA a long term storage of genetic information?

Yes DNA can hold information .It contains the four bases, Adenine, Thymine, Cytosine and Guanine. the four bases will base complimentary pair in one of four ways A-T, T-A, G-C, C-G.

The single DNA molecule in our zygote contained enough information to specify all the key parameters of your final body construction and operation, including all the instructions of how to form that final organism, step by step, from a single cell.

Also Chromosomes are made up of DNA and chromosomes contain genes- hereditary units of coded information passed from parent to offspring.