What experiment proves that dna is the main genetic material?

Transformation test of pneumococcal and phage infection in bacterial test

These two experiments are direct evidence to prove that DNA is biological genetic material, and there are both * * * and subtle differences in experimental design and conclusion. The comparison is as follows:

Comparison of experimental design ideas

Avery experiment

Bacteriophage infection test.

Think alike

We tried to separate DNA from protein and other substances, and directly studied their different genetic functions.

There are differences in treatment methods.

Direct isolation: DNA, polysaccharide, protein, etc. S-type bacteria were isolated and mixed with R-type bacteria respectively.

Isotope labeling method: Special elements (32P and 35S) of DNA and protein were labeled respectively.

2. The two experiments follow the same experimental design principle-control principle.

3. Comparison of experimental conclusions (or purposes)

Conclusion of pneumococcal transformation experiment: It is proved that DNA is genetic material, but protein is not.

The conclusion of bacteriophage infection test proves that DNA is genetic material, but protein is not, because protein did not enter bacteria.