http://www.scientistsolutions.com/c23-anatomy+and+physiology.html Discuss organization of the body and its functions including organs, tissues, electrophysiology, histology, fixation, immunohistochemistry, exercise, muscle, microdissection… Life Science Discussion en-us sci7feed@sci7.nojunkorherepleasespam.com hourly 1 2005-05-05T12:00+00:00 http://www.scientistsolutions.com/t27227-difficulty+in+patch+clamping+neurons.html I have been trying to patch clamp adult dorsal root ganglion neurons for a while now but can't form a gigaseal. My pipette resistance varies between 2-4 Mohms and I very lightly touch the cells before applying suction. The resistance increases upto 20-100 Mohms but I don't get a gigaohm seal. Would really appreciate if somebody could give me tips on how to patch clamp these cells successfully. My extracellular and intracellular solutions are fairly standard (i.e. high Na outside...]]> Wed, 12 Jun 2013 07:01:40 GMT http://www.scientistsolutions.com/t27217-drug+stability.html ]]> Mon, 10 Jun 2013 14:38:01 GMT http://www.scientistsolutions.com/t26983-gain+and+filters.html May someone explain me in a very simple way what gain and filter really are and how do they work in an amplifier?
I obviously know something but I want to further understand it!
Thank you]]> Thu, 23 May 2013 11:28:07 GMT http://www.scientistsolutions.com/t26932-patch+clamp+and+cell+death.html Appreciate your input!]]> Fri, 17 May 2013 04:21:37 GMT http://www.scientistsolutions.com/t26911-clampex10%2c+multiclamp.html we started to use a fully new Patch Clamp Setup few weeks ago (Clampex 10.3, Digidata 1440A, MultiClamp700B). Last week, due to fabrication failure one of our micromanipulators broke and now we have a big problem, that we can make nice Gigaseals and have almost no noise at all, but we cannot adress the micromanipulator with protocols we have.
What exactly is the problem, we don't know, but it is probably a mismatch in the channel settings and the micromanipulator ...]]> Tue, 14 May 2013 04:22:04 GMT http://www.scientistsolutions.com/t26878-minianalysis+ipscs+calculation.html I have tried to measure Inhibitory spontaneous activity with Minianalysis. I have played with the differents detenction parameters but the detection has not been for my entirely satisfaction. Any hint about setting this parameters (threshold, period to max, time before baseline, etc)?
thanks in advance
]]> Fri, 10 May 2013 01:28:50 GMT http://www.scientistsolutions.com/t26876-strong+leak+vs+strong+kv+currents.html I have observed a developmental reduction in Kv current in a particular set of coincidence detecting neurons. It is widely believed that these neurons also show a developmental increase in leak current. I dont want to argue about whether I have a pure H&H leak or some moderately rectifying leak and I know many of you want more details but I think this is a conceptual question.
Problem:
As these cells age, the membrane seems more difficult to access further compounded...]]> Thu, 09 May 2013 19:13:07 GMT http://www.scientistsolutions.com/t26822-interpreting+event+kinetics_+proximal+v_+distal.html for sometime now i have been interested in how the kinetics and amplitude of events can relate to the location of the active synpase and how this is altered by swapping K+ for Cs+.
I have been looking for a nice summary/article explaining this, but so far I haven't been able to find a nice simple overview.
please correct my assumptions if they are incorrect:
1. Distal synaptic events, in general, exhibit slower kinetics (i.e., slower rise and decay times...]]> Mon, 06 May 2013 07:11:23 GMT http://www.scientistsolutions.com/t26820-how+do+you+prep+your+cdnas_.html I'm patching Cav2.2 channel expressed in tsA201 cells.
I have problems in current size and success rate.
Usually I get only one suitable current size (>0.5nA) in 10 whole cells. Also most of the cells have current near 100pA.
I already checked concentration, 260/280 and 260/230 ratio and they are in adequate range.
However, one of my colleague who also studies calcium channels, examined my cDNAs (alpha1 and others) and he concluded that my cDNA is some...]]> Mon, 06 May 2013 03:24:13 GMT http://www.scientistsolutions.com/t26804-leaking+submersion+chamber+_+constant+detachment+of+the+glass+bottom.html I'm having a rather annoying problem, namely we have got a new patch-clamp set-up in the lab and when I wanted to record ljps yesterday I observed that the coverglass constantly detached from my submersion chamber.
On the previoius set-up we used to seal the chamber by using one layer of parafilm and then "soldered" the glass to the parafilm. It worked fine. Unfortunately I have no chance to go back to using the previous chamber.
I would appreci...]]> Fri, 03 May 2013 00:33:23 GMT http://www.scientistsolutions.com/t26733-making+up+internal+solution.html I am concerned about making up my internal solution, aliquoting into 500ul then freezing. Is this the usual method people use?]]> Tue, 30 Apr 2013 14:44:08 GMT http://www.scientistsolutions.com/t26633-sigmacote+vs+sylgard.html Dear Patch Clampers,
I'm completely new in this field.
I would like to know if someone is using Sigmacote to coat their micropipettes instead of sylgard? Is it better?
Would you please explain to me how to do it, do I need to dip it in the Sigmacote after filling it with the internal solution? Do I need to keep a positive pressure? How long do I have to wait.

Many thanks in advance.
]]> Thu, 18 Apr 2013 06:08:30 GMT http://www.scientistsolutions.com/t26630-hippocampal+slices+for+field+recordings.html I am trying to do some field recording in hippocampal slices but I have a problem.
I think that my slices for some reason are not healthy, because when I put the recording electrode in the stratum radiatum I first see a good fEPSP but it decreases until disappearing in a few minutes. I am using a vt1200 leica vibratome, and after decapitating the animal I put the brain in a becker with chilled modified acsf with sucrose. After doing the slices of 350uM thickness I put the slices ...]]> Wed, 17 Apr 2013 13:00:39 GMT http://www.scientistsolutions.com/t26607-increased+holding+current+after+drug.html I am recording from neurons before and after peptide application.
I have found that peptide application makes my holding current increase (become more negative) by roughly 15%. The change does not occur in the receptor KO ruling out deterioation in recording conditions.
I am using intracellular solution with High-Chloride and Cesium.
What are the possible reasons for seeing the increase in holding current??]]> Mon, 15 Apr 2013 00:13:36 GMT http://www.scientistsolutions.com/t26578-gluconate+versus+methanesulfonate.html ]]> Mon, 08 Apr 2013 08:03:52 GMT http://www.scientistsolutions.com/t26538-osmometer.html Can somebody suggest me a cheap but goodworking osmometer? When I say cheap, I mean a cheaper one than Vapro osmometer for example, which cost more than $ 8000!
Thank you ]]> Thu, 04 Apr 2013 14:36:14 GMT http://www.scientistsolutions.com/t26288-how+to+record+cardiomyocyte+action+potential+at+37+degree+c.html I can't patch on cardiomyocytes to record action potentials at 37 degree C using a perforated patch technique. I tried many things, but failed.
Following the suggestions from this forum, I patched the cell at room temperature. After cell got gigaohm sealed, I turned on the temperature controller. At this moment, I found that it was very easy to loss the cell, because of an electric shock?.
So late on, I made a little bit changes and did as...]]> Thu, 21 Mar 2013 18:23:40 GMT http://www.scientistsolutions.com/t26271-bipolar+stim+electrode+electrophoresis.html Sun, 17 Mar 2013 17:28:26 GMT http://www.scientistsolutions.com/t26256-urgent_+large+voltage+offset+_amp%3b+drifting.html I am in urgent knowing what is wrong with my amplifier (HEKA EPC 10 USB). So thankful if you guys could give me a hand.
I met a problem when using a HEKA EPC 10 USB (with patchmaster) which belonged to another staff in the lab previously.
using test pulse (default setting), when the pipet of the probe dipping into the bath solution, the voltage offset increased a lot (even over 200mV).
If configuring the Gain below 0.02mV/pA, I may see the current signal. I use the "aut...]]> Thu, 14 Mar 2013 18:34:44 GMT http://www.scientistsolutions.com/t26233-qx_314+in+the+internal+solution+for+patch+clamp+evoked+potentials.html I have a very simple question.
If I want to record evoked currents (paired Pulses, eEPSC etc) in whole-cell patch clamp configuration, do I have to put QX-314 in the internal solution?
]]> Tue, 12 Mar 2013 13:16:42 GMT