The determination of regional blood flow via the accumulation of fluorescent microspheres is a concept regularly used in medical research. Typically, the microbeads get extracted from the tissue of interest and are then quantified by measuring the absorption or fluorescence of the incorporated dyes without further separation from the medium. However, in that case the absorption spectra of different dyes can overlap when used simultaneously, leading to an overestimation of the concentration. Additionally, background absorption from the medium can be problematic. Therefore, a high performance liquid chromatography method for the simultaneous detection of four dyes (orange, crimson, yellow-green and red) incorporated in different microbeads in samples from biological media such as organ tissue (brain, heart and kidneys) was developed. Since for biological samples often a large sample size is required for sufficient statistics, the method was optimized to yield very short run times. With this method it was possible to detect very low concentrations of only one microsphere per gram of organ tissue. By applying this sensitive quantification technique, it was demonstrated that the application of microbeads for perfusion measurements might not be reliable due to different organ distributions in each animal.

区域血流量的测定通过荧光微球的积累是医学研究中经常使用的一个概念。通常，微珠从目标组织中提取出来，然后通过测量掺入的染料的吸收或荧光进行定量，而无需从介质中进一步分离。但是，在那种情况下，当同时使用时，不同染料的吸收光谱可能会重叠，从而导致浓度的高估。另外，从培养基中吸收背景可能是有问题的。因此，开发了一种高效液相色谱方法，用于同时检测来自生物介质（例如器官组织（大脑，心脏和肾脏））的样品中不同微珠中掺入的四种染料（橙色，深红色，黄绿色和红色）。由于对于生物学样品而言，通常需要大样本量才能获得足够的统计数据，因此对该方法进行了优化，以使其产生非常短的运行时间。使用这种方法，可以检测到每克器官组织只有极低浓度的一个微球。通过应用这种灵敏的定量技术，证明了由于在每只动物中器官分布的不同，将微珠用于灌注测量的应用可能并不可靠。