Protocol and reagents are available mouse and human neutrophils isolation kits from Miltenyi Biotec Inc :Order no. 130-097-658 and stem cell technologies company.
Cayman Chemical also has a kit for isolating mouse neutrophils, though not specifically from blood. Our listing for it is here: http://www.linscottsdirectory.com/products/cayman-chemical-company/Neutrophil-mouse-Isolation-Kit-5631521