Wide-field lensfree imaging of tissue slides

We developed a new imaging tool that can help pathologists in recording wide-field images of tissue slides. We present a simple cost-effective lensfree imaging method to record 2-4 mu m resolution wide-field (10 mm(2) - 6 cm(2)) images of stained and unstained tissue slides. To our knowledge, our method is the first technique that enables fast (less than 5 minutes) wide-field lensfree imaging of such dense samples. Multiple holograms are recorded with different wavelength illumination, and a multispectral algorithm is used to retrieve both amplitude and phase. Our method can be used to retrieve images of stained tissue slides. For such absorbing object, the useful information is included in the modulus of the reconstructed complex field. Our method can also be applied to retrieve images of unstained tissue slides, where the useful information is in the retrieved phase. This technique is much cheaper and compact than a conventional microscope and could be made portable. Moreover, it enables wide field unstained tissue slides imaging, which could quickly provide useful information, for example on frozen section biopsies, when a rapid diagnosis is needed during surgery.