 Overview
About IGOR Pro
Versions:
What's New
Features
Imaging
Force
Acquisition
Analysis
Modification
Lithography
Help
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Force Acquisition
The MFP3D software interface allows up to five data channels to be collected in a single pull. Data can be collected at a sampling rate up to 50 kHz, meaning that a one second force plot will have 50,000 data points in it. Absolute and relative triggers allow for both positive and negative slopes for all data channels. There is also an interface to allow you to control the X-Y position of the scanner where the force plot is performed. Simply take an image, click where you want to do the force plot, and then do it. For example, this way you can see where the DNA chain is sitting, do a few stretches on a tail of the chain, and then do a few stretches on a loop of the chain. [No more blindly doing pulls over the entire surface and then spending the next month sifting through the tens of thousands of force plots to find the handful you care about.] Also built into the force acquisition interface is the ability to pause in mid pull, which we have called "dwell". You can dwell for a set period of time, and then continue on the pull. In addition, there is an ability to do reverse pulls in that the piezo first retracts and then goes forward. In this manner, you can leave the tip in contact with the surface for an extended period time, allowing slower kinetic interactions to occur, and then separate the tip and surface to monitor the forced separation.
Force Analysis
"Display"— A flexible interface has been provided to display any collected or calculated data type vs. any other data type. You can plot time on the Y axis and dissipation on the X. The interface treats calculated data types the same as any collected data type so that you can plot Force, Separation, Dissipation, Loading Rate, etc. It is also very easy to display only certain sections of the data. For example, you can show only the dwell data; or both the trace and retrace, but hide the dwell. We have also included a few WLC models in the force analysis software. For example, you can fit multiple stretching events to a single chain model with multiple attachments, such as domain unfolding, or to a multi-chain model each with a single attachment. You can also hold any parameter constant, or constrain it to remain within a given range. Additionally, the multiple responses can be fit with the same persistence length (see Fig 1).
Force Modifications
It is quite easy to recalibrate the optical lever sensitivity in the off-line software. It is then just one more click to apply that value to all the force plots in the directory, and just one more click to save them all again. You have enough to do without having to go through repetitive mind-less hoops that other software packages force you to jump through. An easy to use interface is provided to offset the data in the X and Y axes. Also, extensive help files are provided to help guide you in creating your own custom modifications to the data. |
