[Histonet] DAKO ARK and Ki-67

[NIDAL E MUVARAK]

Hello. I've been using the DAKO Ark kit to stain for Ki-67 in mouse lungs and arteries. My positive control is mouse spleen, which gives me nice dark brown nuclei. However, I've been getting intense, specific staining in the airways of the lung, even for the negative control, where I replace the primary antibody mixture with just diluent buffer. This shows up also in the experimental tissue as well. I know it's not background since the vasculature in the lung shows no staining. The alveolar space has quite a bit of "brown spots" that lead me to think that I had positive staining in the lung nuclei, but since the negative control showed that, I'm guessing it's false positive. Anybody had this problem before with lungs or other tissue? If someone has any suggestions on how to treat this problem, I'd be very grateful if they can help. Thank you for your time.

Regards,

Nidal E Muvarak
Associate Research Specialist
Vascular Tissue Biomechanics Laboratory
Department of Biomedical Engineering
University of Wisconsin-Madison
1550 Engineering Dr.; Rm. 2158
Madison, WI 53706-1609
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http://vtb.bme.wisc.edu