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Hi Doug,
An HCS machine can definitely be used for less demanding microscopy tasks but do be mindful about what you are trying to accomplish. The big advantage of HCS is the throughput of getting numbers from images of your samples. That may sound obvious but the compromises to accomplish this goal are generally significant.
The lower N.A./dry objectives are often favored because of autofocus issues. The reflective positioning used by most vendors keeps you close to a surface of the plate or slide but generally doesn't account for sample variation. In thicker - but not too thick - samples, this is less of an issue. For monolayers you'll have a significant percentage of out of focus images. Without fast, image sample based autofocus, confocal imaging on a 0.6 N.A dry objective is a bit of an optical trick to enable crisper images for slightly out of position optics.
HCS is a little strange in that the acquired images could be thought of as just intermediate data waiting to be processed into final measurements. On something like a plate reader, you might not normally care what that looks like and focus more on accuracy and precision of the final well to well numbers. Because those intermediate data sets are images, it's very natural to dive in and see what's there.
The other big thing I'd look at is the software. Many of the systems can technically acquire image data from slides, plates etc but they really aren't designed to do so as you might expect. This varies greatly by manufacturer, but because of this focus on high-speed automated image acquisition/throughput, they might not have very usable joysticks and basic flexible controls you'd think would be easy for quick snap by snap users.
There's nothing wrong with any of this and you can get very nice images from these systems. It's more about being aware of the tradeoffs and the intended use.
Best,
Casey Laris | DiPath Inc. | Twitter | Mobile: 858-829-9501
On Jun 4, 2012, at 12:44 PM, Seitz Arne wrote:
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> To join, leave or search the confocal microscopy listserv, go to:
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>
> Hi Doug,
>
> first of all it would be extremely helpful if you could specify/name the confocal principle the HCS instrument(s) is/are based on.
> I assume that they are spinning disk based (thus all following comments refer to this technology):
>
> The use of lenses without immersion media is recommended if you want to scan an entire 96/384 well plate. Unless you have a dispenser which is "refilling" the immersion media. Without such a device you risk that the objective is running out of immersion media. But if you are not planning to do multi position experiments you should be able to use oil/water immersion lenses with these systems as well.
> Then it is just the well-known trade-off between a point scanning confocal microscope and a spinning disk microscope (you should probably find dozens of posting concerning this topics here, otherwise it is nicely summarized in the "Handbook of Confocal microscopy" J. Pawley, 3rd edition).
>
> In short:
> Spinning disk: + faster, wide-field detection scheme, less photobleaching. - less good optical sectioning capabilities, fixed pinhole size
>
> Thus spinning disk microscope are well suited for live cell imaging, less ideally suited for fixed specimens. So does the HCS instrument if is based on this technology.
>
> Best regards
> Arne
>
>
> ---------------------------------------------------------------
> Arne Seitz
> Head of Bioimaging and Optics Platform (PT-BIOP)
> Ecole Polytechnique Fédérale de Lausanne (EPFL)
> Faculty of Life Sciences
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> CH-1015 Lausanne
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> Phone: +41 21 693 9618
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>
>
>
>
>
>> -----Original Message-----
>> From: Confocal Microscopy List
>> [mailto:[log in to unmask]] On Behalf Of Cromey,
>> Douglas W - (dcromey)
>> Sent: lundi 4 juin 2012 19:25
>> To: [log in to unmask]
>> Subject: confocal HCS instruments - are they ready to occasionally replace a
>> confocal microscope?
>>
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
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>>
>> Colleagues,
>>
>> My supervisor has been contacted by one of the high-content screening
>> device companies. They are pitching an HCS device with confocal scanning
>> abilities. Since the HCS instrument can scan multi-well plates and microscope
>> slides, as well as provide environmental conditions for live cells, he was
>> wondering if it would be suitable as an entry-level confocal for some of our
>> users with non-demanding and/or functional live-cell assay kind of needs?
>>
>> I recognize that every optical instrument has compromises, are there
>> compromises that we don't want to make? Seems like most of the HCS
>> systems favor dry lenses, with corresponding lower NAs at any given mag.
>>
>> The one concern I have is that the device might allow people to collect bad
>> data faster. See Dave Piston's recent comment in Nature entitled "Research
>> tools: Understand how it works", Nature 484, 440-441 (26 April 2012)
>> doi:10.1038/484440a
>>
>> I am particularly interested in hearing from people who might have
>> experience with both point-scanning confocals and HCS instruments.
>>
>> Thanks.
>> Doug
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