Western Blotting - BCIP/NBT visualization (Jul/02/2008 )

Hello all-
Can anyone tell me why a secreted protein from supernantant would appear as a white smear after NBT/BCIP staining. I used a another purified protein as a control and it worked (purple bands against white background). Is this protein degraded? Or too concentrated?
Thanks

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Now, is there no end to woes in our field? First time I heard this

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I had similar problems if the protein is far too abundant the staining doesn't seems to work good, however I cannot say that it's the only reason it might as well be another explanation but Yes I experienced that as well

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Is the white smear at the correct position (size) in the gel? I would also like to know the content of the culture medium you used. I had experience that white smear could be caused by albumin when using NBT/BCIP.

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Recombinant baculovirus expressed protein in insect cells using sf900 medium. It is a uniform smear (no size correlation possible)

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almost the same problem here, see attachment

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