Found: SciFi science experiment brought home turns humans into collective blob

I can remember the entire plot but can't remember the book. So here's a brief summary.

A man is fired and brings home his samples from work by injecting them into his arm. He was working on intelligent life I think. Either way, they merge with him and began to speak to him. His friend/co-worker comes to check on him one day and finds him in the bathtub, about to release all of the organisms down the drain and into the world. His friend, horrified of what might happen to humanity, uses the hairdryer to electrocute and kill him. However, the organisms had already transferred onto from an earlier handshake and were merging with his cells. Each person he touch at this point has also been infected. As the organisms merge with people, they melt/dissolve and join one collective thought. The friend and his wife merge into this while holding one another. The story jumps to a girl who is the lone survivor in new york. The phenomenon has not spread outside the US. The collective blob speaks to her, asking if she would like to merge with them, as she is immune to the natural process for some reason but can join them if she wishes. Her family and everyone else is there.

Blood Music by Greg Bear

That's it! Thank you so much!!!

>3 hermonieg11: You're welcome!