IMAGING MELANIN IN MELANOCYTES

描述（由申请人提供）：长期目标是早期诊断恶性黑色素瘤。它被提议测试一种可能性，恶性转化修改黑色素的物理特性。物理特性将由荧光监测。我们建议将正常细胞的黑色素荧光与一系列不同侵袭程度的黑色素瘤细胞系的黑色素荧光进行比较。荧光将通过改进的共聚焦显微镜从少量分子中收集。少数分子的荧光应该是恶性转化早期事件的准确指标，因为它不是在黑素细胞的整个黑色素群体中平均的。当试图测量少量分子的荧光时，共聚焦显微镜是首选的仪器。然而，商用仪器无法检测到少于1000个分子。为了降低这个数字，通过用半导体探测器代替真空管和对信号进行数字处理来提高灵敏度。初步结果表明，这种改进使灵敏度提高了两个数量级。黑色素的荧光是由红外光的吸收引起的。同时测量了荧光的强度、寿命和光谱三个参数。该方法很重要，因为它可以扩展到对皮肤样本的原位测量。这些改装相对简单、便宜，而且不局限于某一特定品牌的乐器。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.