Qkine vascular endothelial growth factor isoform 165 (VEGF165) is more biologically active than a comparable alternative supplier protein

VEGF165 is commonly used with human-induced pluripotent stem cells or embryonic stem cells-derived endothelial cells for developing human vascular tissue models. It has many applications including its use in neural research involving oligodendrocyte precursor cells, Schwann cells, astrocytes, and microglia.

Qkine VEGF165 (Qk048) is a highly pure and potent 38 kDa homodimer, disulfide-linked consisting of two 165 amino acid polypeptide chains. It is animal origin-free, carrier protein-free and tag-free to ensure high and consistent bioactivity.

• VEGF165 (Qk048) was bioactive in a quantitative luciferase assay with an EC50 of 0.5 ng/ml (14.4 pM).
• This was more bioactive than an alternative supplier, which had an EC50 of 1.4 ng/ml (37.6 pM).

Qkine VEGF165 was found to be more bioactive than VEGF165 from an alternative major supplier. Bioactivity was determined using a luciferase reporter cell line which stably expresses the KDR (VEGFR-2) receptor. Cells were treated in triplicate with a serial dilution of Qkine VEGF165 (Qk048, green) or or an alternative supplier protein (Supplier 1, black) for 6 hours. Firefly luciferase activity was measured and normalized to control Renilla luciferase activity.

Qkine recombinant proteins are more cost effective and have the advantage of having high and consistent vial recovery. They are highly pure and animal origin-free, giving lot-to-lot consistency in bioactivity for long-term reproducible culture of stem cells and organoids.