The CD4+CD62L+ T Cell Isolation Kit II has been developed for the improved isolation of CD4+CD62L+ T helper cells from spleen and lymph nodes. The new kit allows the isolation of naive CD4+ T cells with even better purity and recovery due to refinement of the depletion cocktail, including the addition of a CD25 and an anti-TCRγ/δ+ antibody.

CD62L (L-selectin) is highly expressed on naive T cells and down-regulated upon activation. It is also expressed on a small subset of memory T helper cells, the central memory T cells, which can be distinguished from naive T helper cells by their high expression of CD44. Furthermore, CD62L is expressed on most thymocytes, naive CD8+ T cells, B cells, dendritic cells, macrophages, NK cells, neutrophils, eosinophils, regulatory T cells, and TCRγ/δ+ T cells. For isolation of CD4+CD62L+ T helper cells, the non-T helper cells as well as regulatory T cells and γ/δ T cells are depleted by indirect magnetic labeling using a cocktail of lineage-specific biotin-conjugated antibodies against CD8a (Ly-2), CD45R (B220), CD49b (DX5), CD11b (Mac-1), and Ter-119, as well as antibodies against CD25 and TCRγ/δ in combination with Anti-Biotin MicroBeads. Subsequently, CD4+CD62L+ T cells are positively selected from the enriched CD4+ T helper cell fraction with CD62L (L-selectin) MicroBeads.