The immune system serves as the core defense mechanism against foreign and harmful invaders in the human body. As the "special forces" of adaptive immunity, B lymphocytes recognize antigens via B cell receptors (BCRs, i.e., immunoglobulins, IG), while T lymphocytes utilize T cell receptors (TCRs/TRs) to initiate precise immune responses. The collective diversity of functional BCRs and TCRs within an individual constitutes the immune repertoire. Its dynamic characteristics determine the breadth and efficacy of antigen recognition and response, while also reflecting the evolution of immune status. The N-nucleotides region of IG and TR molecules contains a highly variable domain termed the variable (V) region. Within the V-segments, three hypervariable loops-complementarity-determining regions (CDR1, CDR2, and CDR3)—serve as antigenbinding domains. Among them, CDR3 is formed through V(D)J recombination, involving the joining of V-genes with diversity (D)-, and joining (J)-segments. Due to nucleotide insertions or deletions at V(D)J junctions, CDR3 exhibits the highest diversity and directly interacts with antigens, making it the focal point for immune repertoire analysis. NadPrep IGTR Multiplex PCR Library Prep Kit is multiplex amplification-based library preparation kit. It utilizes hundreds of primers targeting IGH, IGL, IGK, TRA, TRB, TRG, and TRD loci for adaptive immune antigen receptors to efficiently enrich CDR3 regions across the immune repertoire, enabling precise assessment of B and T cell diversity and clonality via NGS. This kit features a modular primer design with two independent primer mixes: IG Primer Mix (covering IGH/IGL/IGK) and TR Primer Mix (covering TRA/TRB/TRG/TRD), supporting both single-tube (IG or TR) and dual-tube (IG + TR) workflows. This kit supports 50-2,000 ng of gDNA or cDNA (reverse transcription to generate 1st-strand cDNA) as initial samples. Libraries can be sequenced directly on Illumina® platforms or circularized using the NadPrep Universal Circularization Kit v2 (Cat # 1002241) for MGI platforms. PE150 sequencing is recommended. Workflow 1st PCR (Multiplex) Amplification Library Evaluation IG Primer Mix/TR Primer Mix Multiplex Index Primer Mix #

Flexible Combination of IG/TR Primer Mixes in Separate Tubes for Precise Amplification of Target Regions Spiking 0.001% of a mixture of RAMOS and JURKAT cell line gDNA into 2 μg leukocyte-derived gDNA, libraries were prepared using NadPrep IGTR Multiplex PCR Library Prep Kit, with independent amplification (IG-only or TR-only) or combined amplification (IG + TR). Table 1. Clone list generated by analysis tool. Source Cell Line Clone List Generated by Analysis Tool Reads Count Rank Reads Count Rank Reads Count Rank Figure 1. CDR3 diversity analysis using the NadPrep IGTR Multiplex PCR Library...