Corning? Poly-D-Lysine, 20mg, is used to culture a wide variety of cell types, particularly neurons, glial cells, and transfected cells. 

Source
Synthetic

Quality
Shown to promote cell attachment and spreading of rat cerebellar granule cells
Found negative for bacteria, fungi, and mycoplasma

Molecular Weight
500-550 kD

Preparation and Storage
Stable for three months at 2° to 8°C (lyophilized) or three months at -20°C (solubilized

Handling
Recommended concentration: 2.5-5 μg/cm2 of growth surface depending on cell type

Formulation
Lyophilized from aqueous solution; reconstitute in dH20