What is Optical projection tomography (OPT) ?

To generate 3D images in OPT a series of images is captured of the sample as it rotates. Each line of pixels in these images is then back projected to generate a cross section through the sample. The process of back projection is illustrated in Figure 1.

By joining the back projected images from every line of pixels a complete 3D model is generated.

Figure 1

Figure 2

The 3D models in ZFAP were generated by imaging the autofluorescence of paraformaldehyde fixed zebrafish. Samples were bleached using hydrogen peroxide to remove pigmentation and cleared using benzyl alcohol:benzyl benzoate.

Figure 2 shows a scan of a 7mm long zebrafish specimen.

Similarly to the example in Figure 1 these projection images can be used to generate a cross section through the sample (Figure 3).

Once the cross sections have been generated and used to generate a 3D model. The model can be virtually cut to generate sections in other planes, such as those in ZFAP.

Figure 3