The agglutination chart shows basic grading: 0, 1+, 2+, 3+ and 4+ reaction strengths.
Negative (0): Red cell button entirely resuspended and not visible agglutination
1+: Red cell button entirely resuspended with many small aggregates present
2+: Red cell button entirely resuspended with several medium sized aggregates present, clear supernatant
3+: Red cell button entirely resuspended with few medium to large sized aggregates present, clear supernatant
4+: Red cell button entirely resuspended with one large sized aggregate present, clear supernatant
