In the small lab of the Northern California Community Blood Bank, swift hands process and package blood, plasma and platelets while machines shake, spin and freeze the small bags of bodily fluids.

This lab next to St. Joseph Hospital in Eureka is the heart of North Coast blood distribution. Here, the workers take in raw, untested blood, prepare it for testing, and separate it into its desired parts before pumping it off to hospitals.

Their work — and the dedication of hundreds of repeat donors — doesn't just help Humboldt residents who need life-saving transfusions to treat everything from cancer to car crash injuries. The blood bank here also takes in so much blood that half the red blood cells collected and processed in Humboldt are sent elsewhere, shipped out by plane to blood banks around California. That makes Humboldt a bigger regional giver, proportionately, than some big cities including Sacramento. The North Coast's donations — and the number of people who donate — are well above the national average.

"It says a tremendous amount about your community" to have such donation prowess, says Leslie Botos, the public affairs spokeswoman for BloodSource, a large blood bank based in Sacramento. By comparison, BloodSource sends about 30 percent of its blood supplies out of its 26-county area.

How does Humboldt manage it? One pint at a time, with a constant eye on the future.

Because blood products are perishable, the blood bank needs steady lifetime donors. (The flurry of donor interest that follows any disaster is great, but it's not what keeps a constant supply on hand.) As regular donors age or become too ill to give, recruiters need to pull in 3,000 new ones annually, according to Jo Anna Leppek, the blood bank's donor recruiter.

In a pair of swingy shell earrings and a bright, floral blouse, Leppek has the upbeat energy of a party planner. She's heard every vampire joke there is. When she tells people what she does, she says, they tend (after the jokes) to tell her why they don't give blood: time, bad experiences with needles, restrictions and so on. That's when she goes to work.

Lots of the hurdles that people mention aren't really a problem, she says. Tattoos used to require a one-year deferral, but as of July 1 there's no wait as long as you got your ink in a licensed shop. Piercings just need to be completely healed. Most diabetes, blood pressure and cholesterol medications are fine. In fact, only a handful of medications, such as Accutane and Clavix, pose a problem for donation.

As for alcohol and marijuana, Leppek says, "I don't care if you had beer with lunch or if you get high every day." And if you're worried about privacy, rest assured: The contents of your blood are totally confidential. If the blood bank finds certain disqualifying problems, you'll be notified and advised to see your doctor. After that, your donation is discarded.

On a sunny July afternoon, the blood bank lab is bright, calm and clean. It doesn't smell of antiseptics like a hospital might, but it evokes one, with white lab coats and the hums and whirs of medical equipment.

Here, whole blood is separated into four products: red blood cells, which carry oxygen from the lungs to the rest of the body; platelets, which induce clotting and stop bleeding; plasma, which aids the exchange of minerals and maintains the body's pH balance; and cryoprecipitate, which is a processed type of plasma rich in clotting factors.

When lab workers receive thick, cloudy plastic bags filled with blood, they put the bags in a centrifuge, where they are spun until the platelets, plasma and red blood cells separate. Workers then squeeze the plasma into a new bag, using an optical sensor to maximize the plasma without letting red blood cells in. Platelets, with their murky sepia color, and other products are kept in special proprietary bags designed to prevent exposure to air.

Then the plasma is flash frozen (down to negative 58 degrees Fahrenheit), the red blood cells are refrigerated and the platelets are held at room temperature — though they have to be agitated by special machines (basically a rack that jiggles all day long) to prevent them from clumping. Small sample tubes of each are collected and quickly flown off to Portland (via San Francisco, usually) where they are tested for infectious diseases. Portland is home to one of the American Red Cross's National Testing Laboratories.

This is a crucial yet time-gobbling step in the flow of blood from donor to recipient. The Portland lab pools samples sent in from several blood centers and bathes them in nucleic acid to identify virus fragments.

Blood bank Technical Director Chris Stedlund says positive tests are a "really rare occurrence," with only 0.3 to 0.5 percent of the blood collected here testing positive — most commonly for hepatitis C. If infection is found, or if the donated blood is so high in fat that testing can't be done, the blood bank writes or phones the donor and recommends visiting a doctor. Stedlund says she's seen a positive HIV result only once or twice in the 12 years she's worked for the blood bank; those donors are notified in person.

Testing is one of the blood bank's largest costs, consuming $750,000 of its $5 million in expenses from July 1, 2011, to June 30, 2012. Between shipping costs and the testing itself, the blood bank pays about $50 per sample, says John Gullam, director of donor resources.

Typically, the blood bank gets test results the day after sending the tubes off, but flights between fog-soaked Humboldt County and San Francisco are prone to delay and cancellation, and that can sometimes delay testing for days during stormy times of year.

Once the blood bank gets the thumbs-up from Portland, the blood products are packaged, finalized in a computer system and labeled. Then they're ready for distribution.

"This is the county's blood supply," says product manager Matthew Stuart, as he opens a large freezer door. [Full disclosure, Stuart is a personal friend. — GSG]. A swath of arctic air pours out, the window in the walk-in's door fogs up and it's clear why large parkas hang on coat racks just outside the cooler. Platelets are boxed, labeled and ready to be delivered to hospitals in need.

Next door to the freezer is a refrigerator with the red blood cells. In this cooler, there are only a few dozen neatly arranged crimson pockets with their blood types printed boldly on the front. It doesn't look like much, but the blood bank's supply is in good shape, Stuart explains, particularly with the "universal donor." "O-negative is booming — it's great."

Only 6 percent of the population has O-negative blood, which is usable by all blood types. That means that when a patient comes into the emergency room and needs blood immediately, he or she can be given O-negative on the spot and tested for blood type later. O-negative blood that is cytomegalovirus negative (or CMV-negative) is even more rare. Cytomegalovirus is common and usually harmless to healthy adults, but blood transfusions for infants, pregnant women and children being treated for leukemia must be CMV-negative.

Part of Stuart's job is to coordinate with local hospitals, as well as blood centers out of the area, to make sure everyone has what they need. Hospitals keep a short-term supply of blood bags on site — usually in a household-size refrigerator or freezer.

Platelets are in the highest demand. Red blood cell use is leveling off, blood bank officials say, because of blood conservation practices in hospitals. And — locally, at least — almost nothing goes to waste. Of more than 13,000 donations collected in 2012, only 80 samples expired.

Botos said there are blood banks, which she declined to name, that forego the "local first" mantra of blood banking for "local only," promising donors that their blood won't leave the area. This leads to high rates of expired blood and doesn't increase donations. In her experience, people are happier knowing that their blood will go to use somewhere in the country rather than potentially spoiling waiting for a local recipient.

These life-saving fluids only last so long. Frozen plasma keeps for a year. Red blood cells are good for 42 days. Platelets last just five days.

So Leppek, Stuart and the rest of the blood bank staff perform a constant balancing act — meeting local needs, supplying other blood centers and preventing labor-intensive products from going to waste — all while struggling with people's donating habits.

It's easy for people to think of donating when tragedy strikes, whether local teens are hurt in a car accident or scores are injured in the Boston Marathon bombings earlier this year. But usually, the blood that helps victims of a traumatic event was donated beforehand. That happens through active recruitment, all year round.

Leppek admits it's hard not to sound ghoulish asking for people's blood. For this, the blood bank employs the only creatures more reviled than vampires: telemarketers. Most of its six callers are high school students, and each makes somewhere around 300 calls a night. None of these calls are to new donors; instead, they ring up people who've already given and are eligible again after 56 days, letting them know where upcoming drives or bloodmobiles will be.

Along with taking donations at its lab, the blood bank has three bloodmobiles, which travel from Garberville to Crescent City. Inside, they look like a cross between an ambulance and an RV. As soon as you step in there's a small bench seat for filling out the questionnaire and a side table with bottled water, juice boxes and a package of oatmeal raisin cookies. Costco donates the snacks weekly, to keep donors' energy up and keep them from fainting from low blood pressure and blood-oxygen loss.

Very few people like to be stuck with a needle, and even fewer like to fill out medical forms. There are some 50 boxes to check on a touchscreen questionnaire, and many are personal: weight, medications, sexual history, travel to countries with malaria or mad cow disease, time spent in prison, and even whether you ate any recalled Townsend Farms Antioxidant Blend frozen berries. Not all these things are deal-breakers, and some "yes" answers require only a deferral period.

The FDA is sticking to its controversial "lifetime deferral," though, for men who have sex with men. Opponents say the lifetime ban is discriminatory and doesn't take into account newer and more accurate methods of blood screening, but the FDA considers the ban the best way to keep the blood supply safe.

Around the country, according to Leppek, blood banks are turning increasingly to incentives — tote bags, T-shirts, even donor points that can be redeemed for merchandise via websites. In contrast, at any of the Northern California Community Blood Bank's donation sites, Leppek says, "you're not leaving with anything but good feelings." Donors never meet or even know of the people their blood helps. There is no tax write-off. The nonprofit blood bank is banking on the desire of the people of Humboldt and Del Norte counties to do good.

It seems to work. In Humboldt and Del Norte combined, 4.2 percent of the population donated blood at least once in 2012, about one-third higher than the national average of 2.9 percent.

And many donors gave repeatedly, making the amount of blood donated per capita much higher. During the past 12 months, the 163,000 people in Humboldt and Del Norte counties donated 15,000 units of blood — a ratio of 9.5 percent. The national average is roughly half that, just 5 percent, according to an estimate by the Association of American Blood Banks.

And ultimately, all those donors, all the powerful medical machines, shaky flights, acid baths, sub-zero temperatures and steady coordination lead up to one thing: helping someone in need.

"You make sure to care for your own, and when you're able to collect more than that, you help others," Botos says. "Bottom line: If blood's not there, someone's going to die.