List mode

The digital data from the flow cytometer are collected in list mode files that contain a record of all of the fluorescent events associated with each individual cell in a sample. For any individual cell, the number of events collected is dependent on the number of fluorochromes utilized in the analysis that bind to the cell, which can be amplified by increasing the variety/number of lasers utilized to excite the fluorochrome. These raw data can then be analyzed on-line or off-line by software provided by the manufacturer of... 

The complexity of the data generated by multiparameter flow cytometric analysis means that the scatter and fluorescence measurements from individual cells are stored on the computer in the form of a list (list mode data). This means that the relationships between measurements on individual cells is preserved, and these relationships can be explored by effectively rerunning the analysis on the computer. 

When subsequently recording data from cells, use the scatter gate as a live gate if your flow cytometer has this facility This ensures that most of the list mode data recorded relates to lymphocytes. 

Record list mode data, using the flow cytometer set up as in Section 3.3. 

The number of files per disk is given as the number of samples (of 10,000 cells each) whose list mode data (4-parameter/ 1024-channel resolution) after acquisition can be stored to media of the indicated size. The capacity in bytes of the different media is representative but will vary with the formats of different computing systems. Similarly, different acquisition software will require more or less extra storage space for the housekeeping information that is stored with each sample. Prices of media are illustrative, but will vary considerably from place to place and over time. 

The data stored in FCS format are usually list mode data. As described above, this means that, in a four-parameter cytometer, four numbers are stored for each cell. A 10,000 cell data file will consist of a long list of 40,000 numbers, with each set of four numbers describing each cell in the sequence in which it passed through the laser beam. By retrieving the stored data, each cell can be analyzed again, and the intensity of each of the four signals for that cell will be known and can be correlated with each other or with the intensity of the four signals from any (or all) other cell(s). This type of list mode... 

The scanner is designed to recognise coincidences where events occur in two opposing buckets within a resolving time of 12 ns. In normal operation, only coincidences between two elements in the same ring or adjacent rings (of the 8) were accepted, but for PEPT use this restriction was removed. The data acquisition system of the scanner was also modified so that coincidence data is recorded in list mode with time stamps at 1 ms intervals. 

The 5x5 strip detector used in this work (Figure 1) was fabricated using a photomask technique to make the lithium and boron implants. Our laboratory data acquisition system consists of 10 spectroscopy channels, each with a 13-bit ADC, permitting strips to be analyzed individually. The ADCs are read out through a CAMAC crate with a Macintosh computer. Events are stored on disk in list-mode for subsequent processing. 

A feature of data acquisition that is becoming of greater interest in PET is that of list mode. In this, the events are not stored over preselected time frames in... 

A parameter list may contain all the objects. A procedure may send and receive values (modes in, out and inout supported) but a function only sends values in its list (mode in supported). 

---