And so, who does he experiment on with his first injections? Himself, his family, myself, and Jason and McCloud.

7 seconds sound clip from the Robot Monster (1953) movie soundboard.

You can hear this line at 00:26:50.401 in the Blu-ray version of the movie.

Quote context

[...]

- Ro-Man spoke to us over the view screen. He said that we are the last five people on earth.

- Is he lying, or are there any other people?

- Two more: Jason and McCloud.

- But why them? That doesn't make sense.

- Oh, doesn't it?

- Look, the Professor here spends his entire life trying to discover a serum, an antibiotic serum that will cure all diseases, even the common cold.

- And thanks to his wise choice of assistants, he manages to achieve his goal.

- And so, who does he experiment on with his first injections? Himself, his family, myself, and Jason and McCloud.

- Therefore, the great antibiotic is also the immunizer to Ro-Man's death ray.

- And I thought it was the electronic barricade around the house!

- Well, that may prevent Ro-Man from finding us and blowing us up...

- Which is nothing...

- But against the sweep of the death ray, it's powerless.

[...]