Fluorescence A property of molecules to absorb light at one wavelength and emit light at a longer wavelength. Flow cytometers detect Fluorescence emission at a 90 degree angle to the exciting light beam.
Forward Scatter (FSC) 前向角 A parameter measuring light scattered less than 10 degrees as a cell passes through the laser beam. The FSC measurement is related to cell size.
G0 Phase of cell cycle designating cells that are quiescent and have not yet entered the growth cycle. Normal cells in this phase have exactly one set of chromosome pairs.
G1 Phase of cells cycle in which cells are committed to division. These cells have the same number of chromosomes and the same amount of DNA as GO phase cells. They are about to enter S phase where they synthesize DNA.
G2 Phase of cells cycle in which proliferating cells have duplicated their DNA and formed two sets of chromosome pairs, in preparation for division. G2 follows the S phase and precedes the M (mitosis) phase.
Gain 增益 An adjustment that modifies amplifier responses. Increasing the gain increases the electronic pulse (and the relative fluorescence intensity value and the channel value) in response to a light signal.
Gate 翻译过来后还是觉得称之为“gate”好！A boundary that defines a subset or sub-population of events. Gates are set by drawing boundaries around the subsets on data plots (dot plots or histograms). Use gates either for data acquisition or analysis. Inclusive gates select only the events that fall within (and on) the boundary. Exclusive gates select only the events that fall outside of the boundary.
Live gate 与上面的“gate”不同，是作为记录的条件的gate，不在gate之内的数据不被存入电脑！Gate through which any data from the flow cytometer/computer parallel interface must pass before acquisition. Any data outside the gate does not enter the computer.
Haploid 单倍体 Having one set of single chromosomes. Reproductive cells, like eggs and sperm, are haploid.
Histogram A data plot of a single parameter. This displays either the relative fluorescence intensity value or the channel number on the x axis and the number of events on the y axis.
Linear scale 线性The scale on which the output is directly proportional to the input. When the control is set at Linear, the voltage measured is directly proportional to the channel into which the event falls.
Logarithmic scale 对数 The scale on which the values increase logarithmically. This scale is used when the instrument is set to LOG. There are four decades across the 1024 channels on FACScan (256 channels per decade). The scale ranges from 1 to 10,000. For FACScan, the number of decades is fixed.
M Phase of the cell cycle, mitosis, during which a cell divides into two. This precedes GO/G1 and follows G2. M phase and G2 cells contain the same amount of DNA and the same number of chromosomes. In normal cells, this is the tetraploid number (4N) of chromosomes.
Marker 就是第五篇中的一张图上面的M1，M2等。作为统计时的分界区域限制。A line separating regions on single parameter histograms that are treated statistically separate. See cursor.
Parameter A measurement of light intensity, either scattered or emitted fluorescence, from a particle as it passes through a laser beam. For all five parameters (FSC, SSC, FL1, FL2, FL3) the height of the electronic pulse that is generated is used. In addition, for cell cycle analysis CellQuest software can measure either FL2 area and FL2 width (for staining with propidium iodide) or FL3 area and FL3 width (for staining with 7-amino-actinomycin D).
Photodiode 光电二极管，将光信号转化为电信号。A semiconductor device used to detect light and generate an electrical current. Typically used in forward scatter (FSC) detection.
Photomultiplier 光电倍增管 A photodetector, with adjustable voltage, that translates optical tube (PMT) signals into electrical current. PMT detectors are used for SSC and fluorescence parameters. Increasing the PMT voltage, increases the output signal for a given amount of light.
Ploidy 倍性 The number of chromosomes present in the cell. The amount of DNA in a cell gives an indication of the ploidy, but is not directly proportional. See Haploid, Diploid, and Aneuploid.
Pulse 不是脉搏，是脉冲！The electronic signal generated by a particle (cell or nucleus) in the flow cytometer.
Rate The number of events per second processed by the computer.
Reference Sample 就是作为一个内标的样本，通过它可以对一些物质进行定量检测！（这就是为什么在一些帖子里面，我们总是说流式是个定性，半定量工具，要做到半定量或定量，需要内标。不是所有的数据都可以定量的。） A sample of known DNA content mixed with an experimental sample to provide an internal standard.
S Phase of the cell cycle, DNA synthesis, in which the cell duplicates its DNA.
Scale The maximum number of events displayed for a channel in a histogram. A low scale number magnifies the data.
Side Scatter (SSC) Also called 90o scatter or right angle scatter. Light scattered at a 90 degree angle as a cell passes through the laser beam. This measurement is related to the internal granularity or complexity of a particle.
Singlet A single particle (cell or nucleus), which a flow cytometer records as one event.
Threshold 阈值，在流式中，这是个很重要的概念！ The lowest channel number for a selected parameter for which an event may be recorded. The flow cytometer sends to the computer only events above the threshold level.
