Detection of clonal immunoglobulin and T cell receptor gene recombinations by polymerase chain reaction (PCR)-based methods

Both the TCR and Ig genes are comprised of multiple gene fragments divided into Variable (V), Diverse (D), Joining (J), and Constant (C) regions. During T and B cell maturation, the lymphocytes undergo a process known as somatic recombination in which individual V, D and J regions are combined to form unique TCR and Ig, respectively. Standard primers are designed to bind DNA sequences within V and J regions and allow for the detection of unique TCR and Ig. The finding of a preponderance of a single TCR or Ig within a population of lymphocytes suggests a clonal population of cells.