Google does recognize quotations! You may be referring to Glen Cathey's recent article:
Just don't copy your strings that have quotes from WORD documents - do what the article says or type them in Google
Yes very true google does take quotes.
If you type this "digital negatives" - no. of results is -279,000
If you type this digital negatives - no. of results is -1,370,000
That means there is a difference and it does recognize.