Insect/mammal. cell cultures

[Curt Ashendel]

On 4 Feb 95 18:05:35 GMT, 
Robert Kuhelj  <robert.kuhelj at ijs.si> wrote:

>We' d like to set up a baculoviral expression system for heterologous
>protein production. We do not want to invest a great deal of money in a new
>laboratory and since we already have quite well equipped mammalian cell
>culture laboratory (CO2 incubators, sterile hoods etc.), we'd be very
>grateful if anybody could comment on the following:
>
>1. Can the same room be used for mammalian and insect cell cultures and
>for baculoviruses?

Yes.  No problem.  I have been doing it for three years without a problem.

>2. Can even the same sterile hood be used for all of the previously
>mentioned purposes?

I have no problem doing it.  What is the risk?  The virus cannot infect 
mammalian cells, and the insect cells can't grow in mammalian cell medium.

>3. Which company sells insect cell lines incubators? By the way, in
>Current protocols in mol. biol. it is said that the cells can actually be grown
>on the benchtop provided that the temperature is between 25 and 30 oC. Any
>comment?

I use a microbial (convection) incubator on a bench.  They are much less 
expensive than water jacketed incubators and work fine, except that their 
temperature control is not as precise as the more expensive jacketed 
versions.  The convection incubator I use (obtained for nothing from 
a colleage who no longer needed it) maintains the 27C temperature 
needed by these cells but it is very close to room temp. This makes it a 
bit subject to changes in ambient room temp (such as on hot summer days and 
cold winters).  For more accurate temps, I have heard that some people keep 
microbial incubators in their cold room. 

The cells definitely grow much faster at 28C than at 27C and much more 
slowly at 25C. Our ambient temp is 23 to 24C so it is not practical for us 
to skip the incubator. Since good cell health is so important for proper 
transfection, plaque assays, and expression, I do not recommend letting the 
culture temperature vary with room temp unless that is your only 
alternative.  

BTW, I acutally do spinner flask cultures on a magentic stir plate on the 
bench (in a culture hood actually), since the heat of the stir plate motor 
actually warms the culture perfectly to 27 to 28C. This beats putting the 
stir plate in the incubator and having to downward adjust its temp setting
due to the extra heat generated.

Curt Ashendel
Purdue University
West Lafayette, IN
ashendel at aclcb.purdue.edu