Hi,

Polybrene can be toxic in high concentrations . You could try 8ug/ml, 4ug/ml and compare. We have used 4 ug/ml in the past for BHK cells and it has worked well.

How long do you incubate with the polybrene +/- virus?

Thanks

Thanks for your response Angel!

I tried polybrene@ 4ug/ml and 8ug/ml, and saw clumping with both. I resuspended the cells in concentrated virus+polybrene, added them to the wells of the culture plate & spinoculated @250g for 1hr. I then looked at the cells under microscope before returning the plate to the incubator, and that’s when I noticed clumping. And they continued to look clumped after 24hours, while the cells from control and (-)polybrene wells look perfectly fine!

Could you inoculate without spinning? This might allow cells not to clump.

Thanks