Quantitation within-image

A positive consequence of multi-image analysis is the recovery of quantitative information. At this point, it should be taken into account that quantitation from images measured in reflection is never as accurate and precise as from images measured in transmission. The more representative the surface scarmed is from the rest of the sample, then the more reliable the quantitative information will be. When referring to quantitative information, it is possible to differentiate between within-image and between-image quantitation. 

Figu re 2.18 (a) Scheme followed to obtain within-image quantitative information % of signal contribution) ... 

Fluorescence microscopy, which has been applied by Jain and co-workers in their studies of interstitial diffusion [20, 21] and lymphatic flow, can be used for measurements within the tissue of a living animal, provided that the tissue can be accessed by light. This access can sometimes be obtained by installing window chambers in the tissue [22]. Multi-photon fluorescence imaging, an important new technique introduced by Webb and colleagues [23-25], promises to broaden the applications of this technique, since quantitative fluorescence imaging can be performed in three-dimensional specimens, even specimens that scatter light. 

The within-image quantitation is more correctly described as the signal contribution of a certain constituent to the overall signal. The relative signal contribution over the global image signal can be expressed by sq (%) defined as... 

Gonczy This is very difficult to quantitate. As you have seen from the immunofluorescence images, there are many microtubules on either side in wild-type moreover, anaphase B takes places within a couple of minutes. Therefore, it will be difficult to uncover potential transient changes in microtubule numbers using fixed specimens. However, we have generated a green fluorescent protein... 

Benninger, R. K. P., Koc, Y., Hofmann, O., Requejo-Isidro, J., Neil, M. A. A., French, P. M. W. and de Mello, A. J. (2006). Quantitative 3D mapping of fluidic temperatures within microchannel networks using fluorescence lifetime imaging. Anal. Chem. 78, 2272-8. 

The other useful operation available within the Fourier space analysis is a cross-sectioning of images, which allows us to obtain quantitative information about their similarity or differences [218]. The correlation function C(r) is calculated as... 

In Section II.3 we have seen that a specific chemical species existing in a given physicochemical environment is characterized by specific values of 7) and T2, and that this fact is important both in the implementation of imaging pulse sequences to obtain quantitative information and in the modification of the pulse sequences to image selectively one species and/or phase within the sample. While exploitation of relaxation time contrast is not likely to become a routine approach for chemical mapping in reactors, there will be niche applications in which it will continue to have use—three of these are identified below. The limitations of the approach derive from that fact that the relaxation times characterizing a system will not only be influenced by chemical composition but also by temperature and the proximity of the molecules to a solid surface or interface. The three case studies illustrated below in which relaxation time contrast has been used with considerable success are (i) an... 

Based on the qualitative and quantitative analyses of a two-dimensional fluorescent image scan using a low laser power, areas within the field can be chosen for rescanning at a higher killing laser power. This results in the selective cell death of those cells that meet a specific fluorescence-labeling criteria, i.e., selecting for those cells that are either above or below a certain fluorescence-intensity threshold value (see Fig. 5). 

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