Antibodies (Abs) are essential components of the adaptive immune system, which can combat infections and other harmful agents. Produced by B cells, Ab is either secreted or expressed on the plasma membrane at the present of B cell receptors (BCRs). Each Ab comprises two heavy chains (VH) and two light chains (VL). The VL each include a constant region varing only across different classes and subclasses of immunoglobulin (Ig), and a variable region characterized by a sequence of highly variable amino acids a