Hi Mary,

Welcome back lady!!  Are you trying to preserve both blood cells AND bacteria?
Going back into my Med tech dark ages, we always fixed smears Gram stain
using heat, flamed the back of the slide in order to fix the bacteria, then
did the classic Gram stain method for smears.  Modern microbiology labs may
not do it this way, aerosol or whatever safety considerations with the open
flame??

However, if you need blood cells and bacteria, that presents a different
situation, what are you planning to stain with, a tissue based Gram stain?
If so, you may be able to get away with NBF or methanol for 10 minutes,
then proceed with the stain (Brown and Brenn, etc)

Gayle Callis