| Question: | What is a micro well format comb? |
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| Answer: | For use with 8 & 12 channel pipette. The micro well comb is designed for use with our larger gel boxes when using a multi channel pipette. These combs were adapted to these boxes, and the most number of teeth with the 9mm spacing were fit onto the combs. More often than not however, the total number was not an even (for even loading see the rapid load combs) multiple of 8 or 12 (ie: the A2 has a 21 toothe comb, as 24 would not fit the pre existing gel size.) |
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| Question: | How can a shorter gel be cast on Owl’s large horizontal devices? I would like to save agarose when I only have half the number of samples I usually run. |
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| Answer: | From time to time, there is a need to cast a shorter gel on a large tray, such as our A2. This is usually because a smaller number of samples are being electrophoresed and there is a desire to conserve agarose. Owl created the Chameleon Casting Dam to accommodate shorter gels on our larger units. The Dam is manufactured with heavy aluminum which seals the agarose upon contact, allowing shorter gels to be cast and run. It is free standing so the chosen length is not restricted.
Owl offers wall combs for almost all of our devices to accommodate this need. Wall combs are simply one tooth combs that will fill up most of the area of the tray when placed in any comb slot on the tray. Tape is used to seal up the area around the comb. Agarose can be poured into the area in front of the comb and will not pour into the rest of the tray. See the instructions for wall comb use on our Technical Support page. |
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| Question: | Please explain Notched vs. Offset Glass. |
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| Answer: | Notched and offset glass is available for all Owl vertical units. To form a casette, all units require a blank piece of glass and an offset or notched piece of glass. Notched glass has two "ears" that are left behind when a cut is made in the middle of the top of the glass. Offset glass is about 2cm shorter than a blank piece and doesn't have "ears" on the sides like notched glass. Both offset and notched glass allow the gel and samples to make contact with the upper buffer chamber. Offset requires sponge tips on the side spacers, which take th place of the notches on notched glass. The advantage of offset glass is that it is more rigid. Notched glass is easier to use and does not require the addition of sponge tips on the side spacers. |
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| Question: | Bubbles get trapped at the bottom of my gel and I have to use a bent needle to try to squirt them out. |
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| Answer: | When the gel cassette is placed in the running buffer, voids in the gel trap air. There are two main sources of voids. The most obvious one is when a bottom spacer is used to cast the gel. When the gel polymerizes and the spacer is removed, the space left behind will trap air. Even if the cassette is put into the device at an angle. The other is due to the contact inhibition of acrylamide polymerization due to many materials that are employed as seals in the casting stand. These bubbles are harder to see and dislodge (using bent needles or pipettes).
Owl's casting methodsd avoid the above problems. The Emperor Penguin line of PAGE devices uses a cast-in-place agarose plug that seals the gel cassette, allows current to flow through, and never allows bubbles to form. The other casting device is the Joey Gel Caster, which uses a plastic "pouch" to retain acrylamide. The bottom of the bag is not flush with the cassette, so a bead of gel is formed outside of the gel plates, thus excluding air from being caught between the plates. |
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| Question: | I have an S3ST-Rex Sequencing Gel system and have a technical question. In addition to analytical DNA separation, I would like to use the rig to purify DNA (prep scale). Will the apparatus accommodate 1.5 mm (and 3 mm) spacers and combs without wearing out the clamps?
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| Answer: | The clamps will not wear out, but the change in the pivot may require that some spacer also be placed behind the comb spine to raise it up to the amount that the glass has been raised and that is easy to do. |
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| Question: | What is a rapid load comb and how does it differ from Owl's micro well combs? |
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| Answer: | These combs were designed to allow accurate, easy loading from a 96-well plate. Each comb has either 9mm or 4.5mm center-to-center tooth spacing and a separate marker lane for easy quality control. These combs differ from micro well combs in that the number of teeth is an even number of multi channel loadings. Often you may find that they have fewer teeth than a similar micro well comb for the same unit. However, the extra teeth of a 21 tooth micro well combs can't be loaded with a multi channel pipettor unless only 5 stips are used for the final loading. |
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