Monday, August 17, 2009
Video games and experiments
Performing a biology experiment is somewhat like playing a role playing video game (RPG). You need to pile a series of success to reach the goal. There are two types of the RPGs. One is the Final Fantasy/Dragonquest- type games, and the other is the Zelda/Metroid-type games.
In the Final Fantasy/Dragonquest-type, all you need to do is to give commands to your character to defeat the enemies and to make him/her stronger and stronger. Tactics and strategies are important. The character will gather a lot of weapons and armors, potions, and dozens of other items in the inventory. The inventory has to be well organized by the player.
On the other hand, games like the Zelda series and Metroid, a player needs to develop his/her own skill and technique to control the character. The player needs to learn how to precisely attack enemies and maneuver quickly from their attacks. Very challenging and even stoic.
I assume those who live on biochemistry and molecular biology may prefer the Final Fantasy/Dragonquest type rather than the Zelda/Metroid type.
I prefer Zelda and Metroid. There I could even feel dopamine being gushed out inside my brain when I defeat the final opponent. I feel similarly when I am having a good result from the electrophysiological experiment.
Wednesday, July 8, 2009
AxoClamp 900A problems
After using the new amplifier in several experiments, I decided not to use AxoClamp 900A any more. The reasons are as follows:
1) I could never get used to control the amplifier with mouse and keyboard. Especially when I needed to push and buzz at the same time. I often "clear" the electrode by giving a long buzz, but this cannot be done quickly in the new amplifier.
2) The bath-ground of AxoClamp 900A and that of AxoClamp 2B don't like each other, when they share the same bath ground. When 900A ground was used, then 2B shows 60Hz hum, and vice versa. This is a critical problem. I contacted the customer service and this is what they said:
I am not sure I can give you a solution to this. But perhaps it is how the two instruments are plugged into the wall socket. Try keeping a single headstage grounded, but vary the way the instruments are plugged into their power sockets on the wall or power strip.
Who could provide two different AC sources for a rig? I cannot believe they did not even consider for those who use two amplifies at the same time for one dish.
3) The software (or my PC) has some problem. Something in the USB system in my PC reset periodically. When it happens, the Ch1 tab comes to the top even when I am working with Ch2 tab. I often buzzed Ch1 electrode by accident when trying to buzz Ch2. Those tabs are small and I have to really gaze at the monitor to check which one is in front.
Well, it should work fine if you use it alone by itself and know what cell you are poking. Good enough for doing e-phys while imaging. I installed my old 2B amplifier back to my rig.
1) I could never get used to control the amplifier with mouse and keyboard. Especially when I needed to push and buzz at the same time. I often "clear" the electrode by giving a long buzz, but this cannot be done quickly in the new amplifier.
2) The bath-ground of AxoClamp 900A and that of AxoClamp 2B don't like each other, when they share the same bath ground. When 900A ground was used, then 2B shows 60Hz hum, and vice versa. This is a critical problem. I contacted the customer service and this is what they said:
I am not sure I can give you a solution to this. But perhaps it is how the two instruments are plugged into the wall socket. Try keeping a single headstage grounded, but vary the way the instruments are plugged into their power sockets on the wall or power strip.
Who could provide two different AC sources for a rig? I cannot believe they did not even consider for those who use two amplifies at the same time for one dish.
3) The software (or my PC) has some problem. Something in the USB system in my PC reset periodically. When it happens, the Ch1 tab comes to the top even when I am working with Ch2 tab. I often buzzed Ch1 electrode by accident when trying to buzz Ch2. Those tabs are small and I have to really gaze at the monitor to check which one is in front.
Well, it should work fine if you use it alone by itself and know what cell you are poking. Good enough for doing e-phys while imaging. I installed my old 2B amplifier back to my rig.
Friday, June 26, 2009
AxoClamp 900A
This week I installed a brand new Axoclamp 900A (Molecular Devices) in my rig.
The new amplifier has several neat features. One can save the setting of the amplifier as a configuration. This may be good for doing different kinds of experiments routinely in one rig.
They changed the headstages. This is really annoying.
The new headstage somewhat resembles that of Axopatch, but shorter. There is no rod and it is designed to be attached directly onto the manipulator. And, of course, it won’t fit on our manipulator. We use Siskyou’s micromanipulator. Siskyou provides a “dove-tail” headstage connector, which costs like $175 for each. This is a rip off.
So, I constructed two headstage holders by myself from scratch.
Photo: The old headstage (blue) and the new headstage (black).
The “dovetail” slide connectors were made from plastic plates cut out from the microelectrode box (Sutter). A wooden rod ($0.87) was bought at Home Depot. It was cut, carved, grooved, and epoxy-glued upon the dovetail plate. The tightness of the dove tail can be adusted by putting something under the headstage. I use a small amount of dental wax. The total cost is less than a dollar + my labor.
Another feature I don't like is that there are no knobs on the front face of the amplifier. You need to control the capacitance compensation using mouse, or type in, like 8 μF through your computer. It has to be all controlled by PC. Bridge balancing is automatic. This sounds good, but actually it is not. In a real E-phys experiment, you don't really balance the bridge that accurately, because I don't trust bridge at all for measuring input resistances. I mostly use the bridge to keep the output within the voltage range of your AD converter.
This was my first day of using it. I might change my mind after getting used to this machine. I don't like it so far, though.
The new amplifier has several neat features. One can save the setting of the amplifier as a configuration. This may be good for doing different kinds of experiments routinely in one rig.
They changed the headstages. This is really annoying.
The new headstage somewhat resembles that of Axopatch, but shorter. There is no rod and it is designed to be attached directly onto the manipulator. And, of course, it won’t fit on our manipulator. We use Siskyou’s micromanipulator. Siskyou provides a “dove-tail” headstage connector, which costs like $175 for each. This is a rip off.
So, I constructed two headstage holders by myself from scratch.
Photo: The old headstage (blue) and the new headstage (black).
The “dovetail” slide connectors were made from plastic plates cut out from the microelectrode box (Sutter). A wooden rod ($0.87) was bought at Home Depot. It was cut, carved, grooved, and epoxy-glued upon the dovetail plate. The tightness of the dove tail can be adusted by putting something under the headstage. I use a small amount of dental wax. The total cost is less than a dollar + my labor.
Another feature I don't like is that there are no knobs on the front face of the amplifier. You need to control the capacitance compensation using mouse, or type in, like 8 μF through your computer. It has to be all controlled by PC. Bridge balancing is automatic. This sounds good, but actually it is not. In a real E-phys experiment, you don't really balance the bridge that accurately, because I don't trust bridge at all for measuring input resistances. I mostly use the bridge to keep the output within the voltage range of your AD converter.
This was my first day of using it. I might change my mind after getting used to this machine. I don't like it so far, though.
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