LymphoFirst2 is a recently developed and enhanced medium that has been formulated with extensive expertise to provide superior performance and longer stability. It has been specifically designed for the temporary growth of peripheral blood lymphocytes for chromosome analysis. The composition of LymphoFirst2 includes L-glutamine, pre-screened fetal bovine serum (FBS), antibiotics, phytohemagglutinin-M (PHA-M), and a carefully calibrated concentration of growth factors to promote cell growth.