Learn to be a good Twitter citizen—and a good brand representative—in the virtual world.

Quickly connecting with large numbers of the public at a paltry 140 characters a pop is seductive, but with this great power comes great responsibility. Keep these 5 guidelines in mind for preserving a positive Twitter buzz about your biotech brand.

1. Have a presence. Use it. During the BP oil spill crisis, a fake BP Oil Twitter account lambasted the company with official-sounding tweets.

You don’t want a snarky doppelganger defining your brand’s image before you make your first tweet on behalf of your company. As with the old lottery maxim, you have to be in it to win it.

2. Consider the Internet a permanent record. Nothing ever really dies on the Internet. Even though Kanye West and Sarah Palin have reportedly deleted troublesome tweets, someone, somewhere, is bound to have a screen grab of a negative comment. (Don’t laugh, they often appear on blogs and gossip sites.)

Anything that is typed up, any picture, any audio or video link, can always potentially show up on Google, making it just a few keystrokes away from coming it to light again. Think before you post.

3. Don’t underestimate Twitter’s power. King, an indie R&B group, literally became an overnight success on iTunes and Amazon.com, thanks to having Questlove, drummer for The Roots and the Late Night With Jimmy Fallon show, who raved to his 1.5 million Twitter followers about the group’s EP the day after its release.

Good will was spread in this case, but the spread of ill will via Twitter is definitely possible, too.

4. Remember that Twitter doesn’t exist in isolation. Mixed Chicks LLC, a multicultural hair products company, recently incited a heated debate on skin color and ethnic aesthetics that started innocently on Twitter and spilled over to other Internet locales. I read of the situation on a hair care message board, where several people were denouncing the company.

The takeaway for your biotech dealings? What happens on Twitter doesn’t just stay on Twitter.

5.   Respond with grace. Be certain before you press the “tweet” button that your tone in replies, direct messages, and retweets cannot be construed as defensive, sarcastic, or otherwise uncourteous, as that will do more harm than good.

Twitter is an online party, where the world can rejoice World Cup wins together. On Twitter, people also collectively reflect on, and share support for, tragedies like the earthquakes and tsunami in Japan. And it was one of the sources through which Egyptian dissidents organized to remove President Hosni Mubarak.

Twitter is a community and a source of breaking news. Pay attention to your activities and mentions on Twitter to avoid a #fail, as they say in Twitter-speak.