Method of Measuring Adaptive Immunity

A method, comprising:

• generating a plurality of amplicons comprising rearranged TCR or IG CDR3 nucleic acid sequences from a first sample comprising nucleic acid molecules obtained from lymphocytes from a mammalian subject, using a plurality of V-segment primers and a plurality of J-segment primers in a single multiplex PCR, wherein each V-segment primer is complementary to one or more functional TCR or IG V-region gene segments, wherein each J-segment primer is complementary to one or more functional TCR or IG J-region gene segments, wherein said plurality of V-segment primers and said plurality of J-segment primers are capable of amplifying in said single multiplex PCR at least 104 distinct amplicons representing a diversity of rearranged TCR or IG CDR3 nucleic acid sequences present in said first sample;
• sequencing said plurality of amplicons;
• and
• determining a total diversity of rearranged TCR or IG CDR3 nucleic acid sequences from said plurality of sequenced amplicons of said first sample.