[Histonet] RE-hydrating air dried slides for Pap stain

[Jeffrey Silverman]

Hi Valerie, 

It sounds like you are performing a Pap stain using saline baths to RE-hydrate air dried smears prepared at the bedside, I assume for  staining with Diff Quik stains. 

The rehydration ( not dehydration) takes place in the sodium chloride baths and restores the morphology of the cells to something closer to a wet fixed state. This takes place in 30 seconds.  You then must actually fix the  now rehydrated cells in 95% alcohol. This step should be of sufficient time to completely fix the cells as one would from the start, up to 20 minutes is needed. 
. 
Next the cells need to be rehydrated again, just placed in a water rinse, before staining with hematoxylin and proceeding with the Pap cytoplasmic stains. 

Awareness of these steps should obviate any problems. 

Finally, I wouldn't judge the success or failure of the stain by the color of the slide since different tissue fluid backgrounds and amounts of lysed blood might stain differently.  Check the slide microscoipically to assess the stain. 

Jeff Silverman