weak signal - (Aug/27/2010 )

Hi,

A week back I had successfully stained my mouse xenograft sections using my freshly arrived antibody. However, after 10 days, I'm not able to repeat the staining. This time around I'm getting a very weak or no signal after staining for 10 mins with DAB.

I've repeated using the same protol as I did when I got sucessfull staining. I've made fresh buffers, used the same antigen retrieval. Recently I was able to stain a human specimen with actin and the siganl came out very strong, suggesting that the protocol is working. Any other suggestions are welcome.

You said you repeated the protocol on human sample...were you using the same ab as with the mouse sample? Your ab should not have deteriated in 10 days if kept refrigerated (or even at RT...unless bacterial growth).