*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****
Hi,
Ah, it is true that a sputter coater used
for SEM makes a plasma. This is actually fancier
than what is needed (and certainly you don't want
to sputter metal on your coverslip). But plasmas
are also used for cleaning surfaces. Apparently
they create ozone or something that attacks
hydrocarbons that coat everything. It should be
possible to find a 'plasma cleaner' or 'etcher'
that is not a sputter coater. (Maybe on some
models of sputter coaters you could make a plasma
w/o coating but I think maybe not). EM labs use
them activate grids and other fighing of
hydroarbon menace. Materials Science labs might
have one, or anyone dealing with micro (nano!)
fabrication. The devices I have used are simple,
they have a small chamber whre you put your
coverslips or slides, and they pull a vacuum
(maybe 0.1 % of air, not sure exactly but nothing
too serious), and then generate a plasma in the
remaining air (I guess by using RF coils but I
don't know the engineering details). There is
nice blue/purple glow. This makes glass extremely
hydrophillic. This is useful for lots of things,
including polylysine coating.
Right after plasma coating coverslips,
we add a drop of polylysine to the coverslip,
spreading if needed, and let it air dry. Then put
a generous drop of water on, let that air dry,
and the coverslips are ready. We use them as soon
as possible after that. The next day they are
less sticky.
As ever
Tobias
>
>
>Hi Tobias. what kind of plasma, like with argon
>or something? when you mention EM, you're
>thinking about the gold sputter coating device?
>and after, you still go through HF etching or
>straight to poly-L ?
>good to hear from you
>Jose
>
>Em 12-03-2012 13:32, Tobias Baskin escreveu:
>>
>>
>>Hi,
>> Have you tried to activate your coverslip by putting it in a
>>plasma for 30 sec to 1 min? When we do this, we find that the
>>polylysine coating works much better than when the coverslips are
>>only acid cleaned. Your friendly neighborhood EM lab should be able
>>to provide a plasma for you to try.
>>
>> Hope it helps,
>> Tobias
>>
>>>
>>>*****
>>>
>>>Dear all,
>>>we are trying to image fixed cell spheroids (>100um diameter) on a
>>>leica sp5 inverted confocal microscope. The high resolution
>>>objectives we use have short but sufficient working distance to
>>>analyse the spheres if they attached to the coverslip. However
>>>standard coatings as polilysine are not efficient in immobilizing
>>>them (even if they can initially adhere we loose them extensively
>>>during staining). We tried also particular gels as Q gel but we
>>>were not able to find a reproducible protocol to have them clearly
>>>attached to the substrate instead of being simply embedded in the
>>>gel.
>>>I know that new high NA water-immersion long working-distance
>>>objectives could provide the simplest solution but unfortunately
>>>their cost is quite limiting.
>>>thanks for all the answers
>>>Mario
>>>
>>>--
>>>---PLEASE Note the change in telephone number---
>>>
>>>--
>>>Mario Faretta
>>>Department of Experimental Oncology
>>>European Institute of Oncology
>>>c/o IFOM-IEO Campus for Oncogenomics
>>>via Adamello 16 20139 Milan Italy
>>>Phone: ++39-0294375027
>>>email: [log in to unmask]
>>
>
>--
>
>
>**********************************************************
>Jose' A. Feijo', Professor Catedrático
>----------------------------------------------------------
>Dep. Biologia Vegetal, Fac.Ciencias, Universidade Lisboa
>PT-1749-016 Lisboa, PORTUGAL
>
>tel. +351.21.750.00.47/00/24, fax +351.21.750.00.48
>
>and/ e
>
>Inst.Gulbenkian Ciencia, PT-2780-156 Oeiras, PORTUGAL
>
>tel. +351.21.440.79.41/00/19, fax +351.21.440.79.70
>__________________________________________________________
>e.mail: [log in to unmask] or [log in to unmask]
>
>
>**********************************************************
--
_ ____ __ ____
/ \ / / \ / \ \ Tobias I. Baskin
/ / / / \ \ \ Professor
/_ / __ /__ \ \ \__ Biology Department
/ / / \ \ \ 611 N. Pleasant St.
/ / / \ \ \
University of Massachusetts
/ / ___ / \ \__/ \ ____ Amherst, MA, 01003
www.bio.umass.edu/biology/baskin
Voice: 413 - 545 - 1533 Fax: 413 - 545 - 3243
|
