Macromolecule blotting is a process performed after gel electrophoresis. An alkaline solution is prepared in a container. A sponge is placed into the solution and an agaros gel is placed on top of the sponge. Next, nitrocellulose paper is placed on top of the agarose gel and a paper towels are added on top of the nitrocellulose paper to apply pressure. The alkaline solution is drawn upwards towards the paper towel. During this process, the DNA denatures in the alkaline solution and is carried upwards to the nitrocellulose paper. The paper is then placed into a plastic bag and filled with a solution full of the DNA fragments, called the probe, found in the desired sample of DNA. The probes anneal to the complementary DNA of the bands already found on the nitrocellulose sample. Afterwards, probes are washed off and the only ones present are the ones that have annealed to complementary DNA on the paper. Next the paper is stuck onto an x ray film. The radioactivity of the probes creates black bands on the film, called an autoradiograph. As a result, only similar patterns of DNA to that of the probe are present on the film. This allows us the compare similar DNA sequences of multiple DNA samples. The overall process results in a precise reading of similarities in both similar and different DNA sample.