Isotype controls for MO and NE

Hello,
I was wondering if anyone can come up with solutions to tackle a 
recurring problem we have with analyzing monocyte and neutrophil 
markers using flow cytometry. The isotype controls rarely fall within 
the lower left quadrant when we look at these cells. This becomes a 
big problem for setting gates to analyze samples. For Lymphocyte 
populations on the other hand, isotype controls are really tight.
Any suggestions anyone?

Thanks in advance

Kanika Ghai

Graduate Student
The Ohio State University