The overall goal of this procedure is to convert a cell phone camera to a fluorescent microscopy platform or a fluorescent imaging cytometer. First, the fluorescent emission is collected through an attached lens that has been placed between the cell phone, camera unit and the sample of interest. Next, a simple plastic filter within the attachment rejects the scattered excitation light, which creates a dark field background for fluorescent imaging, converting the camera phone into a fluorescent microscope or imaging cytometer.
In the final step, a picture or video is taken of the fluorescent particles of interest using the camera in night mode. Ultimately, fluorescent beads or cells can be imaged and characterized by the cell phone camera. The main advantage of this technique over existing masses, like using conventional fluorescent microscope, is that cell phone based microscope is compact, lightweight, and cost effective, and has potential for use in point of care diagnostics.
At the resource limited settings where conventional healthcare services are not available To assemble the opt fluidic, widefield fluorescent microscope begin by placing the Plano convex lens into the optical attachment within its specific lens holder position. Then place the plastic filter onto the filter tray and slide it into the attachment. Next, insert the LED tray into the attachment.
Place the sample glass slides into the sample tray, and then slide the sample tray into the attachment. After facing the LEDs toward the sample clip, the assembled opto fluidic widefield fluorescent microscopy attachment onto the cell phone, such that the extra lens is directly in touch with the cell phone camera lens. Now use the switch on the attachment to turn on the LEDs and image the sample of interest with the cell phone camera.
In night mode. When there is a need to screen large volumes of liquid samples for the detection of rare events, an opto fluidic flow cytometry device can be assembled. Begin by placing the A spherical lens into the attachment.
Then tape the plastic absorption filter in front of the camera lens and slide the microfluidic chamber into the attachment. Now clip the assembled opto fluidic attachment for fluorescent imaging cytometry onto the cell phone, such that the extra lens is directly in touch with the cell phone camera lens, and use the switch on the attachment to turn on the LEDs. Next, connect the microfluidic channel to the syringe pump and deliver the liquid sample into the microfluidic device at a constant flow rate.
Then using the video mode of the cell phone camera, capture a movie of the fluorescent cells flowing through the microfluidic channel to prepare fluorescent microparticle samples. First mix 10 microliters of green fluorescent beads and 10 microliters of red fluorescent beads with 40 microliters of deionized water. Using a micro pipette place 10 microliters of the bead mixture onto a glass slide.
Then use another glass slide to make a sandwich structure. Finally, insert the sandwich structure into the sample tray of the widefield fluorescent microscopy attachment and slide it into the cell phone attachment. To prepare a fluorescently labeled white blood cell sample first transfer 200 microliters of a whole blood sample from an EDTA blood collection tube to a 1.5 milliliter polystyrene tube.
Then add one milliliter of red blood cell lysing buffer to the 200 microliter whole blood sample and mix thoroughly after five minutes, centrifuge the lysed blood sample. Then remove the supernatant resuspend, the white blood cell pellet in 200 microliters of PBS, and gently mix the cells after centrifuging. Again, remove the supernatant and resuspend in PBS.
Next, add five microliters of one millimolar cyto 16 solution to the white blood cells and incubate the sample in aluminum foil for 30 minutes. Then after spinning down the sample, again, resuspend the labeled white blood cell pellet in more PBS and transfer five to 10 microliters of the cell sample onto a cover slip. Place a second cover slip on the top of the sample and then insert the sandwiched cover slips into the sample tray.
Image the sample using the cell phone fluorescent microscope attachment. Alternatively, the labeled cells can be continuously delivered through the microfluidic channel with a portable battery powered automated syringe pump. Then using the cell phone camera in video mode capture a fluorescent microscopic movie of the flowing cells.
Fluorescent cells or particles can be imaged in static mode such that without any fluidic flow, a very large sample field of view with the spatial resolution of about 10 micrometers can be observed. For example, in this figure, green and red fluorescent beads have been imaged. A decent image quality is achieved over a field of view of about 81 millimeters squared toward the edges of the central field of view.
However, there are aberrated regions here, cell phone images of fluorescently labeled white blood cells are shown. This inset shows a digitally zoomed cell phone image of fluorescently labeled white blood cells cropped from the main image. In this inset, compressive decoding results for the first inset are shown the decoded image exhibits a similar level of clarity to the same cell sample viewed on a 10 x objective with a conventional fluorescent microscope of the same field of view.
Off to watching this video, you should have a good understanding of how to convert your cell phone into forensic microscope or imaging cytometer, allowing imaging characterization and content of forensic bead or cells.
