Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of blood-screening systems specialist Immucor (Nasdaq: BLUD) surged 30% today after the company agreed to be acquired by private equity firm TGC Capital for $1.97 billion.

So what: The all-cash deal values Immucor at $27 per share and represents a 30% premium to its Friday closing price. According to Immucor Chairman Joseph Rosen, the move will allow shareholders "to realize significant, immediate value while at the same time allowing Immucor to remain well-positioned to continue pursuing growth opportunities."

Now what: When you make 30% in one morning, taking at least some dough off the table seems like the prudent thing to do. Under the terms of the agreement, Immucor may "shop" for better proposals until Aug. 15, but holding out for a dramatically better offer seems risky. After all, with high-quality rival Bio-Rad Labs (NYSE: BIO) now trading at a P/E discount to Immucor, you won't have to look very far to roll your bet over.

Interested in more info on Immucor? Add it to your watchlist.

Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Fool's disclosure policy always gets a perfect score.