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G'day Aleksandr,

Do you require this lens for confocal and or multiphoton microscopy? If so you should follow George's advice.

If you purchase a high NA 20x (or 25x) lens. Then this will perform perfectly at zoom 1 with a wide field of view, and as described be George zoom in 2 or 3 times and have the equivalent performance of a 40 or 60x. Saving you the cost of several lenses.

If however if you need a 40x for conventional microscopy, then you may need a 40x.

Mismatching objectives from manufactures may be possible, but is not a good idea, especially if you want to use confocal microscopy to optically section deep within tissue. The loss of chromatic correction I think would result in very significant loss of signal strength as you go deeper into tissue with confocal. Maybe not so problematic if using for conventional microscopy or multiphoton with NDDs.

I wouldn't mix manufactures lenses on confocal if you were hoping for good depth penetration. Which is likely the reason why you want a water immersion lens in the first place.

Cheers Steve

Stephen H. Cody

On 26/02/2011, at 11:43 AM, George McNamara <[log in to unmask]> wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
> 
> Leica has a 20x/1.0 NA objective lens, and, if I recall correctly, a 25x/0.95NA - if this is on a laser scanning confocal, zoom these lenses to 2x. NA is what matters.
> 
> On 2/25/2011 10:10 AM, Jurkevic, Aleksandr wrote:
>> *****
>> To join, leave or search the confocal microscopy listserv, go to:
>> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
>> *****
>> 
>> Hello,
>> 
>> Leica doesn't currently have a 40x water immersion objective although I heard that they have one in the pipeline. Has anyone used a 40x water from a different manufacturer with success on this frame?
>> 
>> 
>> Aleksandr Jurkevic, PhD
>> Associate Director
>> Molecular Cytology Core
>> University of Missouri-Columbia
>> 120 Life Science Center
>> 1201 E. Rollins St.
>> Columbia, MO 65211-7310
>> 
>>   
> 
> 
> -- 
> 
> 
> George McNamara, PhD
> Analytical Imaging Core Facility
> University of Miami