How would you recommend checking the point spread function?

The point spread function (PSF) describes the response of an imaging system to a point source or point object. As such, the PSF is important for colocalization. To check the PSF, it is recommended to acquire Z-stacks with 10–20 nm steps and use, for example, 100 nm molecule repeats, allowing the user to measure PSF in the sub-resolution area.

It is also recommended to always use Olympus immersion oil with Olympus lenses. This is because both the refractive index (RI) and the Abbe number (also termed the V number) are important. The Abbe number is an approximate measure of the material’s dispersion, which describes how the RI changes with wavelength. A high Abbe number indicates low dispersion. Using Olympus immersion oil avoids chromatic aberrations caused by dispersion. Make sure to check the expiration date on the immersion oil bottle.

Finally, ensure the coverslip is 1.5H cover glass, and consider the RI of the mounting medium.

What other kinds of objectives does Olympus offer?

Olympus offers a wide range of objective lenses for any number of applications in both the life sciences and material sciences—choosing the right lens can sometimes be overwhelming! However, Olympus has simplified the process by providing an online objective finder tool, making it easy to dynamically filter your options by feature and application. If you need additional support, you can speak to your local field rep or one of our microscope experts.

Are the X Line or A Line lenses better for laser scanning microscopy and why?

Both X Line and A Line lenses are appropriate for laser scanning microscopy. The Olympus X Line lenses provide high quality chromatic aberration correction from 400–1000 nm, resulting in exceptional color reproducibility. Additionally, the high numerical aperture enables acquisition of high-resolution, bright images while good edge correction (flatness) facilitates high-quality images with greater uniformity from the center to the edge, even with a large field of view.

A Line lenses are also great for super resolution and are an important choice to consider for your specific application. For instance, the A Line silicone oil immersion lenses are recommended for live cell applications as silicone oil does not dry at 37 ˚C (98.6 °F) and its RI remains constant. Moreover, silicone oil lenses offer a long working distance to enable observation at a deeper tissue level and across broader fields. Specifically, the Olympus A Line silicone 30x lens is ideal for organoid and zebrafish imaging.

Is there any benefit to using X Line objectives for clinical whole slide imaging?

Yes, clinical applications are one of the areas in which the X Line objectives are extremely beneficial. For instance, when using a laser scanning confocal microscope in neuroscience applications, it is common to want to image an entire section to be analyzed collectively; this requires tile stitching. However, an uneven field of view can necessitate taking additional zoomed images to reduce stitching artifacts. In turn, this increases the amount of photo-damage to your sample and increases the amount of time taken for your total scan. The Olympus X Line objective achieves high resolution without the need to zoom and take additional images.

Can X Line and A Line objective lens be used for microscopes that are not from Olympus?

Although it is not recommended, if the lenses fit the thread (RMS), then Olympus lenses can be used in conjunction with other brands. However, many manufacturers have changed the thread to prevent this. Moreover, the magnifications set by other manufacturers vary due to components such as tube length, and chromatic aberrations are produced due to different corrections of other components. Immersion oil from other suppliers or unsuitable cover glasses can lead to chromatic shifts, and using third-party microscopes may exacerbate this. The flatness/sharpness in the edge area is also unlikely to be satisfactory as only Olympus objectives are corrected for a 26.5 field number.

What is the coldest temperature that an objective lens can tolerate?

We recommend temperatures between 5 °C and 40 °C (41 °F and 104 °F). However, it’s critical that you maintain a consistent temperature as changes can cause expansion and contraction in the optic. Some customers even store their objectives in incubators.