A violent weekend for Chattanooga leaves empty shelves at blood assurance.

“In particular a shortage of O-, O+, and B- blood cells,” said Dr. Liz Culler. “We have less than a one day supply. There's still no reason to panic.”

Dr. Liz Culler says they typically keep a three to five day supply of blood.

The full-service regional blood center supplies over 70 health care facilities within a 2 1/2 hour radius of Chattanooga.

Culler's goal is to see at least 500 people donate every day.

However, she recognizes 15 percent of those people will be turned away because of conditions like a low red blood cell count.

“We prick your finger to make sure that it's safe for you to donate,” said Culler. “Another common reason may be high blood pressure or high pulse. A lot of people drink those energy drinks these days.”

Culler and her staff are trying to replenish the supply before the Labor Day weekend.

“People are not only not at school or not it works to be able to come and donate, but they're driving a lot more,” said Culler.  “They are getting into a lot more accidents.”

Culler encourages people planning to donate to eat a meal and drink plenty of water before you walk in.

“Come on in, and you can do a questionnaire, and the needle is only in your arm for 10 minutes,” said Culler.  “So you could even do this on your lunch hour.”

To be eligible to donate blood, you must be at least 18 years old, weigh 110 pounds or more, and be in good health.

You can walk-in without an appointment during business hours.

There's also an opportunity to give at a mobile site see locations here.