I need to use double quotes in a string that uses the @ symbol. Using double quotes is breaking the string. I tried escaping with \, but that doesn't work. Ideas?

I need to use double quotes in a string that uses the @ symbol. Using double quotes is breaking the string. I tried escaping with \, but that doesn't work. Ideas?

I believe this should work:
string myString = @"Here is my ""quoted"" text.";
You double the quotes inside a verbatim string to get a quote character.
This makes your given sample:
(@"PREFIX rdfs: <" + rdfs + @">
      SELECT ?s ?p ?o
        WHERE { ?s ?p rdfs:Literal }
              {?s rdfs:label ""date""}");