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Title: DNA fragmentation in a steady shear flow
We have determined the susceptibility of T4 DNA (166 kilobase pairs, kbp) to fragmentation under steady shear in a cone-and-plate rheometer. After shearing for at least 30 min at a shear rate of [Formula: see text], corresponding to a Reynolds number of [Formula: see text] and a Weissenberg number of [Formula: see text], [Formula: see text]% of the sample is broken into a polydisperse mixture with a number-averaged molecular weight of [Formula: see text] kbp and a polydispersity index of [Formula: see text], as measured by pulsed-field gel electrophoresis (with a 95% confidence interval). The molecular weight distributions observed here from a shear flow are similar to those produced by a (dominantly extensional) sink flow of DNA and are qualitatively different than the midpoint scission observed in simple extensional flow. Given the inability of shear flow to produce a sharp coil–stretch transition, the data presented here support a model where polymers can be fragmented in flow without complete extension. These results further indicate that DNA fragmentation by shear is unlikely to be a significant issue in microfluidic devices, and anomalous molecular weight observations in experiments are due to DNA processing prior to observation in the device.  more » « less
Award ID(s):
2011401
NSF-PAR ID:
10411333
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Biomicrofluidics
Volume:
16
Issue:
5
ISSN:
1932-1058
Page Range / eLocation ID:
054109
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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