Getting fixatives off

classic Classic list List threaded Threaded
3 messages Options
Medha Pathak Medha Pathak
Reply | Threaded
Open this post in threaded view
|

Getting fixatives off

Hello All,

I'm doing an experiment that requires patching on to a cell, imaging
fluorescence from a Ca-indicator, fixing the cell while patched and then
repeating the process with the next sample. I'm having some trouble with
remnants of the fixative (PFA & glutaraldehyde) either in my recording
chamber (made of plastic & sylgard) and/or the objective lens affecting
sample health and patching. I'm using an Olympus 100X 1.1 NA long working
distance dipping lens. Instead of cleaning just with water, I tried wiping
the plastic dipping portion of the objective lens with 0.2M ammonium
chloride. For cleaning the recording chamber, I soak the whole thing in
ammonium chloride for a few minutes and then rinse with water. This seems to
work better than water alone.

I wonder whether:
1. NH4Cl might be bad for the objective lens coatings. Would it be ok to dip
the lens in NH4Cl solution?

2. What other ways can I get the PFA & glutaraldehyde off?

Many thanks for your inputs,
Medha
Tim O'Brien Sr. Tim O'Brien Sr.
Reply | Threaded
Open this post in threaded view
|

Re: Getting fixatives off

Medha-

We used to use a 0.1% sodium borohydride solution for quenching those
fixatives for tubulin immunofluorescence, but I have not tried it with
an objective lens present.  It might be worth a try with a non-precious
objective first, or asking the Olympus support about reactions with
coatings, etc.  We used it ice cold, and a bit of gas is released, so
some ventilation is recommended, and small volumes, no sparks or flames.
This would not remove the aldehydes probably, but might reduce
toxicity/reactivity.

You might also quench with a high concentration of tris buffer, which
might result in less toxicity as well.

Tim O'Brien
UNC Chapel Hill




Medha Pathak wrote:

> Hello All,
>
> I'm doing an experiment that requires patching on to a cell, imaging
> fluorescence from a Ca-indicator, fixing the cell while patched and then
> repeating the process with the next sample. I'm having some trouble with
> remnants of the fixative (PFA & glutaraldehyde) either in my recording
> chamber (made of plastic & sylgard) and/or the objective lens affecting
> sample health and patching. I'm using an Olympus 100X 1.1 NA long working
> distance dipping lens. Instead of cleaning just with water, I tried wiping
> the plastic dipping portion of the objective lens with 0.2M ammonium
> chloride. For cleaning the recording chamber, I soak the whole thing in
> ammonium chloride for a few minutes and then rinse with water. This seems to
> work better than water alone.
>
> I wonder whether:
> 1. NH4Cl might be bad for the objective lens coatings. Would it be ok to dip
> the lens in NH4Cl solution?
>
> 2. What other ways can I get the PFA & glutaraldehyde off?
>
> Many thanks for your inputs,
> Medha
>
>  
zhan cheng zhan cheng
Reply | Threaded
Open this post in threaded view
|

Re: Getting fixatives off

In reply to this post by Medha Pathak
hi,
   I think tris buffer is not a good idea, because it also kill cells. NH4Cl should be ok for the objective, or you may try the alcohol.
        zhan cheng