Multispectral lensless digital holographic microscope: imaging MCF-7 and MDA-MB-231 cancer cell cultures

Abstract

Digital holography is the process where an object's phase and amplitude information is retrieved from intensity images obtained using a digital camera (e.g. CCD or CMOS sensor). In-line digital holographic techniques offer full use of the recording device's sampling bandwidth, unlike off-axis holography where object information is not modulated onto carrier fringes. Reconstructed images are obscured by the linear superposition of the unwanted, out of focus, twin images. In addition to this, speckle noise degrades overall quality of the reconstructed images. The speckle effect is a phenomenon of laser sources used in digital holographic systems. Minimizing the effects due to speckle noise, removal of the twin image and using the full sampling bandwidth of the capture device aids overall reconstructed image quality. Such improvements applied to digital holography can benefit applications such as holographic microscopy where the reconstructed images are obscured with twin image information. Overcoming such problems allows greater flexibility in current image processing techniques, which can be applied to segmenting biological cells (e.g. MCF-7 and MDA-MB-231) to determine their overall cell density and viability. This could potentially be used to distinguish between apoptotic and necrotic cells in large scale mammalian cell processes, currently the system of choice, within the biopharmaceutical industry.

Phase Imaging of Human Cells Using Digital Holographic Microscopy

“…[8][9][10][11] DHM has a wide application across diverse domains. [12][13][14] However, these systems encountered limitations in optical resolution due to image resolution camera format size, and the available 3D reconstruction software. This paper described the use of conventional bright field microscopes without modification repurposed for DHM application to explore the resolution possible within the nucleus of human cheek cells.…”

Real world objects: capturing using in-line digital holography, projecting using spatial light modulators

“…A DIHM system was designed, developed and purposely built to image MCF-7 and MDA-MB-231 mammalian cancer cell cultures 12,14 . This was originally done because of its compact footprint compared to the Mach-Zehnder or Michelson interferometers.…”

Lensless multispectral digital in-line holographic microscope

“…The in-line geometry has been applied to electron holography 5,6 as well as microscopy for the study of 3-D trajectories of plankton (copepod nautilplius), 7 imaging microspheres, [8][9][10][11] tracking particles in space and time, 12 inspection of deposits on silicon wafers, 13 as well as for the imaging of cancer cells. 10,11,14 The technique has also been employed to image objects using sources of varying wavelengths and degrees of coherence. 10,13,[15][16][17][18] Digital holography's (DH) genesis dates back to the late 1960s when Goodman and Lawrence used a Helium-Neon (HeNe) laser and a Vidicon camera to capture a 256×256 pixel digital hologram.…”