IMAGING MELANIN IN MELANOCYTES

描述（由申请人提供）：长期目标是恶性黑色素瘤的早期诊断。建议测试恶性转化改变黑色素的物理特性的可能性。将通过荧光监测物理特性。建议将来自正常细胞的黑色素的荧光与来自具有不同程度侵袭性的一系列黑素瘤细胞系的黑色素的荧光进行比较。通过改进的共聚焦显微镜从少量分子中收集荧光。几个分子的荧光应该是恶性转化早期事件的准确指标，因为它不是黑素细胞中整个黑素群体的平均值。共聚焦显微镜是尝试测量少量分子荧光时的首选仪器。然而，商业仪器不能检测少于约1000个分子。为了减少这个数字，通过用半导体探测器取代真空管和数字化处理信号来增加灵敏度。初步结果表明，这种修改提高了两个数量级的灵敏度。黑色素的荧光由红外光的吸收引起。同时测量荧光的三个参数-强度、寿命和光谱。该方法是重要的，因为它可以扩展到皮肤样品的原位测量。这些修改相对简单，价格低廉，并且不依赖于特定品牌的仪器。预计该方法将在小型诊断实验室中得到应用。

DESCRIPTION (provided by applicant): The long-term goal is early diagnosis of malignant melanoma. It is proposed to test a possibility that malignant transformation modifies physical characteristics of melanin. Physical characteristics will be monitored by fluorescence. It is proposed to compare fluorescence of melanin from normal cells with fluorescence of melanin from a series of melanoma cell lines with varying degrees of aggressiveness. Fluorescence will be collected from a small number of molecules by a modified confocal microscope. Fluorescence of a few molecules should be an accurate indicator of early events of malignant transformation, because it it is not averaged over the entire population of melanins in a melanocyte. Confocal microscope is the instrument of choice when attempting to measure fluorescence of a small number of molecules. However, a commercial instrument is unable to detect less than about 1000 molecules. To decrease this number, the sensitivity is increased by replacing vacuum tubes with semiconductor detectors and by processing signal digitally. Preliminary results show that this modification improves sensitivity by two orders of magnitude. Fluorescence of melanin is induced by the absorption of infrared light. Three parameters of fluorescence - its intensity, lifetime and spectrum -- are measured simultaneously. The method is important because it can be extended to measurements on skin samples in situ. The modifications are relatively simple, inexpensive and not tied to a specific brand of instrument. It is expected that the method will find application in a small diagnostic laboratory.