Describe the difference between the experiments of Griffith and Avery, MacLeod and McCarty, and Hershey &Chase?

Excuse me for english, but I'm only an Italian student

Griffith
He was studying a vaccine against Streptococcus Pneumoniae using two different type, R (rough, because it produces a cell wall that prevent the reaction of immune system so that it produce pneumonia) and S (smooth, no cell wal, so it is destroyed by immune system).
He put killed R in some mice and they were ok
He put living S in some mice and they wew ok
He put killed R and living S and they died
observing under the microscope tehir blood he found living R.
So he tought that in R there was something that was able to transform S in R

Avery
Avery carries on Griffith work and took a cell free extract (that means thet there were no membranes, organelles, only biomolucles) of R and put in three different tubes with living S.
In the first he destroyed lipids of the free cell extract
in the second he destroyed proteins of the free cell extract
in the third he destroyed DNA of the free celle extract
In the first and second tubes he found living R, in the third only living S
So he thinks that what can transform R in S (genetic material) was DNA

Hersey and Chase
They were studyng some viruses that kill bacteria, in particular T2. They put in T2 DNA radioactive phosphorus and in T2 proteins radioactive sulpur. They knew that T2 put inside bacteria genetic material but they didn't know if genetic material was DNA or proteins. At the end they found that phosforum was inside bacteria, and they said that DNA was genetic material

Differences

Griffith was studying an other thing and accidentally  took the first step toward modern genetics but he was not so interested about that results so he didn't give so much importance.
Avery heard Griffith ideas and decides to investigate only about this and ideate a very simple experiment, whose results were right but at the time no one trusted him, In fact, the genetic study on bacteria was not considered good and all scientist tought that genetic material was proteins in fact they knew lots of them and they didn't know anithing about DNA
Chase experiment is really more complicated and uses also viruses but his results are irrefutable
DC