Detection of CDRIII DNA in the plasma of patients with B-cell malignancies. (A) CDRIII DNA amplified from the plasma of eight representative patients with NHL, four patients with B-precursor ALL at diagnosis, and two healthy control subjects. PCR-products derived from diagnostic tumor material of one NHL patient (lymph node: LN*, lane 1) and one ALL patient (bone marrow: BM*, lane 10) are included for comparison. Positive β-globin bands show the presence of DNA in all samples. (B) Comparison of CDRIII DNA amplification products in tumor cell samples (T), plasma (P), and serum (S) from five representative patients (two ALL and three NHL). PCR products were cloned and DNA sequences were found to be identical in each patient (summarized in Table 1). Ethidium bromide stained polyacrylamide gels; MW indicates molecular weight markers.