Analysis of leukemia-specific IgH rearrangements in single leukemic cells and neonatal blood spots of a patient with hyperdiploid ALL.

A 2-round nested clone-specific PCR was performed, and products were size fractionated on 2.5% agarose (A) or 4% to 12% polyacrylamide gels (B). (Ai) D_H3-22/J5 rearrangement of 224 base pairs; (Aii) V_H3/D_H3-22/J5 rearrangement of 169 base pairs; and (Aiii) V_H3/D_H2-22/J4 rearrangement of 125 base pairs. (A) SM size marker VIII (Roche, Mannheim, Germany), lane 0, no DNA; lanes 1 to 5, dilutions of leukemic cell DNA into peripheral blood DNA 10⁻² to 10⁻⁶; lane 6, DNA from control Guthrie card; lane 7, DNA from the patient's Guthrie card; lane 8, PCR product from a representative single cell. (B) SM size marker, lane 1, peripheral blood DNA from healthy donors; lane 2, DNA from the patient's Guthrie card; lane 3, DNA from control Guthrie card; lane 4, single leukemia cell; lane 5, dilution of DNA from leukemic cells into peripheral blood DNA 10⁻⁵. Arrows indicate the size of specific PCR products. Sequencing of all PCR products of the expected size confirmed identity with the original rearrangements. These data were reproduced in a second experiment (data not shown).