International sera exchange analyses in relation to DNA sequences: summary report from 1990 to 1994.

One hundred ninety-five sera were tested against over 7,000 cells originating from approximately 100 laboratories in the world during the past 5 years. This collaboration was useful to compare local data with data from other laboratories, although the local panel of cells varied from 30 to 200. In analyzing the reactions of the sera, it was noted that antibodies that react cleanly to well-defined antigens can usually be defined by a single unique amino acid residue. Antisera which appear to be definable by several amino acids (a motif) have reactivities which are more variable.