An array of infectious diseases is transmitted through blood, and while donors are not at risk, an airtight system for blood screening is crucial for those on the receiving end. The U.S. Food and Drug Administration has repeatedly found the Red Cross in violation of blood safety laws, and court documents claim the organization has a poor track record of taking blood from donors with hepatitis and other diseases.

The Red Cross argues that it has invested more than $280 million to meet FDA requirements, and believes "the nation's blood supply has never been safer than it is today." It continues to respond to this and other issues, such as donor recruitment and new concerns like West Nile Virus and Creutzfeldt-Jakob disease.

Sources: CBS News, American Red Cross, American Association of Blood Banks

Only 5 percent of eligible Americans give blood. Studies show that the average donor is a white male between the ages of 30 - 50, college educated and making an above-average income, with women at the same economic level not far behind. The slightly higher percentage for males may be due to the fact that many blood drives happen in the workplace, although the practice has fallen off at some companies in recent years. Most donors have given blood at least once before.

# To donate you must: Be over 17 years of age and weigh at least 110 lbs.

# Be in generally good health

# Not have donated blood in the past 56 days

# Not have engaged in activities that put one at risk for HIV or hepatitis. This includes snorting or shooting drugs, any homosexual relations among men since 1977, or tattooing within the past 12 months.

# Not have lived in the United Kingdom for more than 3 months total since 1980, or in Europe for longer than six months

The World Health Organization's Global Database on Blood Safety found that 80 percent of the world's population does not have access to reliable and safe blood. In the United States, the Red Cross screens its donations at nine specially designed centers, ensuring one of the safest supplies in the world.

There are 11 tests that help determine whether blood is safe for transfusion:

# ABO and Rh: To accurately determine the exact blood type

# Red Cell Antibody: Detects a resistance to red cell antigens which sometimes appears in people's blood following transfusions or giving birth.

# Anti-HIV 1/2: Screens for antibodies to HIV types 1 and 2

# Anti-HTLV I/II: Screens for the antibody to T-cell lymphotropic virus, which can cause a rare leukemia and neurological disease in a very small number of cases.

# Hepatitis B Surface Antigen

# Hepatitis B Core Antibody: Detects an antibody produced during and after infection with hepatitis B.

# HIV P24 Antigen

# Anti-HCV: Tests for hepatitis C

# ALT: Looks for elevated levels of an enzyme that may indicate liver damage caused by hepatitis

# Syphilis

# Nucleic Acid Testing: A new screening method that detects HIV and hepatitis C through DNA screening.

Test results are returned within 18 hours. Blood that is rejected is destroyed and infected samples are confidentially reported to the donor.

The Red Cross collects blood in 36 regions and distributes it nationwide. Though much blood stays in the region where it's collected, it can be sent anywhere as needed. Most blood is donated at mobile sites, through collections at community centers, businesses and schools.

The entire interview and donation process takes about an hour. The donor gives about a pint of blood, which takes about 10 minutes to draw. Samples are placed in vials to be sent to testing facilities to type the blood and ensure it is disease-free.

Blood is usually processed and broken down into its component parts -- red blood cells, platelets and plasma. White blood cells, which help fight off foreign substances in the blood stream but are generally not well-tolerated by recipients, are almost always filtered out.

The Red Cross distributes blood to over 3,000 U.S. hospitals. Platelets can generally be kept for five days, Red blood cells for 35 days, and plasma can be frozen for up to a year.

Your blood type, just like your eye and hair color, is inherited. There is compatibility within many of the eight types, and people who are O negative are called "universal donors," because their red cells can be used in virtually any transfusion. But O negative is only found in about 7 percent of the population, so it is used at a much higher rate than it is donated and is often in low supply. Additionally, people with type AB negative are "universal recipients," because they can receive any type of blood.

Sources: American Red Cross; ARC Penn-Jersey Region

Blood is made of a watery substance called plasma and tissue cells, of which there are three types: red cells, white cells and platelets. Red cells carry oxygen throughout the body and rely on iron -- which gives blood its red color -- to stay healthy. White cells are the body's protectors, and they fight infection by attacking bacteria. There are five types of white cells. Platelets are clear, clotting cells that keep blood both in your veins and in your body when there is a wound.

Giving blood saves lives, and most of the population over the age of 17 is eligible to donate. Some blood banks pay for their supply, but the Centers for Disease Control and Prevention has found that what's collected from paid or family donors is at increased risk for disease, and often does not reach patients fast enough. The Red Cross began collecting blood to aid injured soldiers during World War Two, and its Blood Services unit now fills nearly half the nation's need. A 3-day supply is stockpiled and alerts are issued if this level drops.

An adult will need two to six units of red blood cells, two to four units of plasma and one to 10 units of platelets on average.

An infant, on average, will need one to four units of red blood cells, one to two units of plasma, and one to four units of platelets.

On average one to two units of red blood cells are needed.

A patient may need two to six units of red blood cells and six to eight units of platelets daily for two to four weeks.

Six to 10 units of red blood cells, 20 units of plasma and 10 units of platelets on average.

One to two units of red blood cells on average are needed every other day for two to four weeks, and six to eight units of platelets are needed daily for four to six weeks.

Newborns may need one to four units of red blood cells while in the intensive care unit.

Sufferers need on average 10 to 15 units of red blood cells to treat severe complications.