We appreciate Gerald Leape's tribute to the Red Cross and would like to comment on his letter that appeared Dec. 19. The American Red Cross Washington Regional Blood Services has been on appeal for Type O blood donations since late October. We have taken this action to ensure that there was an adequate supply of this blood type to get us through the holiday season when demand for blood traditionally increases while donations traditionally fall off.

In addition to the Drew Center at 2025 E St. NW, we staff bloodmobiles open to the public at sites throughout the D.C. metro area. In a typical week, we have 25 to 30 public bloodmobiles in operation. Donors can obtain information on the most convenient location by calling 728-6550.

In this holiday period, we will have special ''I Resolve to Give'' bloodmobiles at the Best Western Hotel in Springfield and the Hilton Hotel in Greenbelt open into the early evening hours on Wednesday, Dec. 30. Donors also will be able to donate at the Washington Cathedral on Thursday, Dec. 31, from 10 a.m. to 3 p.m.

Fortunately, the response to our appeal has been good, and we are not in a crisis situation at the moment. However, the demand for blood, especially Type O, is ongoing. And we do need to keep asking the public, through public education channels and through personal telephone calls, to help us maintain a safe and adequate community blood supply. Thank you. FRED DARR Medical Director, District of Columbia Chapter Blood Services, Washington Region American Red Cross Washington