The center said Thursday it tries to maintain a seven to nine-day supply of all blood types.
O-negative can be transfused into anyone during a trauma situation when there's no time for blood typing.
The center says there are fewer scheduled blood drives than usual during the first week of September.
The center provides blood, transfusion products and services to hospitals around New York City, Long Island, New York's Hudson Valley, New Jersey, and parts of Connecticut and Pennsylvania.
