The MP-225 Micromanipulator is designed for the specific use of moving micropipettes in three-dimensional space in increments of micrometers into and out of an optical pathway of a microscope. The system provides for a synthetic 4th axis for diagonal advancement of the pipette; and up to 16 different angles can be configured. Its manual can be found here. Please refer there esp. for construction and setting up the angle of your diagonal mode through the DIP switches on the back of the human-interface device.
The MP-225 Micromanipulator System is comprised of three basic parts: the controller (MP-225), manipulator mechanical (MP-225/M), and a human-interface device called the ROE-225 (ROE = Rotary Optical Encoder). These are pictured above.
All functions necessary during normal operation are provided by 5 push buttons, a MODE Selector and three rotary optical encoder (ROE) knobs located on the ROE input box. Other set-up functions are done via DIP switches located on the back of the ROE box.
Movement#
The three ROE knobs control the three axes of the manipulator (right knob X, left knob Y, and top knob Z). The direction of movement commanded by a clockwise turn of the knob is controlled by a DIP switch (one for each axis) located on the back of the ROE.
Speed#
The MODE Selector changes the speed and the relative fineness of movement of the manipulator when rotating the ROE knobs. Setting 0 is for course movement at high speed and setting 9 is for very fine movement at very slow speed. In practice, most users will find that speed 5 or 6 will provide the necessary fineness of movement for approaching cells. The current MODE setting is displayed in the upper right of the ROE display
Stop/Set#
There is one STOP/SET button. If hit when stationary, SET is performed. If hit during an automatic movement, STOP is performed.
- SOP - Think of this as your panic button when you see your pipette headed somewhere that you don’t want it to go! If you have used the “Stop” button to stop robotic movement, you need to cycle the power off/on and then run Center (see below) to completely recover normal function.
- SET - When held down, the “Stop/Set” button performs a “Set” function in combination with either the “Work Pos.” (or “Center” keys, bit rare usecases for Center). Think of it as a shift key when held down.
NORM/DIAG#
Pressing the “Diag/Norm” button will cause the green LED to light, indicating the MP-225 is in Diagonal mode. When in this mode, rotation of the Z-axis knob produces diagonal movement. A second press will put the MP-225 back into Normal mode. When in diagonal mode, the X and Y knobs remain active, allowing you to re-adjust the X and Y positioning of the pipette as you approach a cell in diagonal mode. Angle of diagonal mode movement is set via DIP switches on the back of the ROE box. (See DIP switch setting instructions in the manual). When using MODE 9 (rotary thumb wheel set to 9) Diagonal mode produces short, quick, impulse-like movement that may be useful in sharp pipette impalements.
HOME#
Cannot be custom set. When pressed, the manipulator will make a move to a factory determined “Home” location along a stereotypic path. The Home location is defined as the location where you would most likely exchange your pipette. It is coordinate 0,0,0 and is maximal up on the Z-axis, maximal right on the X-axis (maximal left on a left-handed manipulator) and maximal front on the Y -axis. The path of the movement is first along the currently set diagonal until either the X-axis or Z-axis reaches its origin (0). Which one of these occurs first is a function of the diagonal angle and the location at the time “Home” is pressed. Once the first limit is reached, the unit will move the two remaining axes simultaneously to their origins (0).
WORK POS#
The Work Pos. button has two functions. When the “Set” button is held down, pressing and releasing “Work Pos.” makes the current location the “Work Position”. A beeper will sound to indicate that the operation is complete and the current location has been saved. Typically, this will be a location where the pipette tip is near your preparation (cells or tissue of interest). When “Work Pos.” is pressed alone, after a Work Pos. has been set and after the manipulator has just made a move to “Home”, then the manipulator will move to the preset work position. The move will occur along the predefined path that the manipulator moved to get to “Home” as described above, but in the opposite direction. This is the reason why “Work Pos.” moves must follow “Home” moves as the move to Home defines the return trip. In either case, the movement along the diagonal as you come in and out of the preparation/dish/bath should assure that the pipette tip cannot hit anything on the way in or out.
CENTER#
Not for routine usage! Center is a function that will normally only be used when the unit is first set up. The Center move should only be done in the absence of a pipette as the manipulator makes large robotic movements to its extreme ranges of motion. To activate Center, press “Set” and while holding it down press and release “Center”. This will cause a prolonged movement in each axis to the end of travel (EOT) sensors beyond the origin (0,0,0). Once the sensors are found, a short move in the opposite direction is made and this location is defined as (0,0,0). Finally, the unit moves to the location (12500, 12500, 12500). This is equivalent to the center of travel of each axis. Once the Center function has been run, each axis is limited (in firmware) to movement between 0 to 25000 microns.
Handedness#
