Worried about colds, flu and other germs? Go ahead and touch those doorknobs and elevator buttons, but watch out for the telephone, fresh laundry and sinks, a top expert advises.

And while you should always wash your hands before making a meal, many people do not realize that they should do so afterwards also, says Charles Gerba, a microbiologist and clean water expert at the University of Arizona.

When people are cautious, they are usually cautious about the wrong things. Germs do not stick where people believe they will. "Doorknobs are usually on the low side," said Gerba, who has conducted dozens of surveys of bacteria and viruses in workplaces and homes. "I guess they are not moist. Never fear a doorknob."

"Keyboards are a lunch counter for germs," Gerba said. "We turn them over in a lot of studies and we are amazed at what comes out of a keyboard." In fact, the average desk harbors 400 times more bacteria than the average toilet seat, says Gerba, whose latest survey focuses on the germiest professions.

Bathroom sinks, are another place. "Sinks are usually high (in bacterial counts) to begin with," Gerba said. "They have got everything a bacteria likes. It’s wet, it’s moist. In a home we usually find more E. coli in a sink than a toilet." Men’s rooms, too. "Usually the dirtiest handles in public restrooms are urinal flush handles," he said.