Capillaries
Glass capillaries are fragile and requires some precaution to work with. Plastic capillaries are non-breakable and cheaper than the glass capillaries. It was therefore interesting to test, if the capillaries performed identically.
For the experiment we compared Roche glass capillaries (left) with Genaxxon polycarbonate capillaries (right). Most, if not all plastic capillaries require their own rotor, since they are of a different diameter than the glass capillaries.
We saw no differences in sensitivity between the two systems, neither in samples with pure template, nor in samples with biological samples (cDNA).
Occassionally we see "jumps" in the cycling curve when using plastic capillaries, possibly because they don't fit quite as tight in the rotor as the glass capillaries, allowing them to misplace slightly in the rotor during cycling. It has no practical importance, though, as it usualy happens long after Ct.
We have not tested other brands of plastic or glass capillaries and recommend that you carry out your own test to make sure that you come to the same conclusion.
