Tom Jerry

Thank you everybody for all of your help!
Fortunately, I have been able to obtain the dimensions of the wells for the "10-well, 1.5mm" gel comb which I have and the "9-well, multichannel compatible, 1.5mm" comb which I was thinking of ordering.

Here are the details, for those who are interested.

The comb is made to fit the width of the gel tray, so combs for the E-4109-1 (9 x 11 gel size) will have product numbers that begin with E-4109.

The width of the tooth is one factor in determining the volume of the well.  The placement of the comb into the gel tray leaves 0.2 cm of agarose under the sample well, so that a 0.5 cm thick gel will have a sample well that is 0.3 cm deep.  Loading volume is calculated as:  Thickness of the tooth (1.0 or 1.5mm) x Width of the tooth x Depth of the sample well (Gel thickness – 0.2 cm).


Width

E-4109-9MC
(9 well, 1.5mm)
7.2 mm
7.2 x 1.5 x 3 =  32.4 microliters
E-4109-10
(10 well, 1.5mm)
6.8 mm
6.8 x 1.5 x 3 =  30.6 microliters





I plan to order this 9-well comb, as it will likely fit my sample volumes.
Thank you to all of those who replied.

Tom

I see, thank you for the information!
Tom

Thank you Trof for your advice,

It is indeed a great idea to reduce the PCR, digestion, and elution volumes. I will consider modifying my protocols. If this works, I may not have to purchase a comb after all
Thank you for also clarifying what "multichannel compatibility" means. Hopefully my manufacturer will tell me that the wells of the 9-well 1.5mm comb are larger than those of the 10-well 1.5mm, as it could just be that they have the same size but just more "spaced out". As you have suggested, I look forward to asking them also about the max well volumes of each of the combs they sell.

Thank you again,
Tom

Thank you very much for your response and suggestion

Yes, I usually use the 10-well 1.5mm comb with 0.75g/75mL (1%) agarose to load my purified and digested PCR products (36 total µL). Like you have mentioned, my goal here is to use the least amount of agarose necessary to reduce the agarose that I have to clean off when I'm gel-extracting and cutting out the bands. We've managed to barely fit our 36 µL by taping around the wells to increase their volumes. Maybe I'm just lazy, but I thought this was a bit time-consuming. Since I'm about to receive a grant for my lab, I wanted to just buy a new comb that could create more loading space so we won't have to bother dealing with the tape every time. But at the same time each comb is $50 so I didn't want to risk buying a new comb that won't solve our problem. I also didn't want to get the 5-well comb because although it would definitely fit the entire sample, there's a lot of agarose around each band to clean up. Currently I'm waiting for the bioexpress person to reply. I've asked them if each well in the "9-well comb, multichannel compatible, 1.5mm thickness" will fit more than the wells I have now. I'm a bit curious about how this "multichannel compatible" comb is different from any of the standard ones that they sell. As long as this "multichannel compatible" comb still provides more volume than my 10-well combs, I'm happy. Too bad they don't provide pictures for these products.

Again, thank you for advice. Perhaps this taping process is something that I just have to bear with, which, I guess is not that bad.
I will see what the bioexpress person says about the 9-well multichannel compatible comb, if they even reply.

Tom