TY  - JOUR
A1  - Reiss, Edda
A1  - Hoelzel, Ralph
A1  - Bier, Frank Fabian
T1  - Synthesis and stretching of rolling circle amplification products in a flow-through system
N2  - Enzymatic isothermal rolling circle amplification (RCA) produces long concatemeric single-stranded DNA (ssDNA) molecules if a small circular ssDNA molecule is applied as the template. A method is presented here in which the RCA reaction is carried out in a flow-through system, starting from isolated surface-tethered DNA primers. This approach combines gentle fluidic handling of the single-stranded RCA products, such as staining or stretching via a receding meniscus, with the option of simultaneous (fluorescence) microscopic observation. It is shown that the stretched and surface-attached RCA products are accessible for hybridization of complementary oligonucleotides, which demonstrates their addressability by complementary base pairing. The long RCA products should be well suited to bridge the gap between biomolecular nanoscale building-blocks and structures at the micro- and macroscale, especially at the single- molecule level presented here.
Y1  - 2009
UR  - http://www3.interscience.wiley.com/cgi-bin/jhome/107640323
U6  - https://doi.org/10.1002/smll.200900319
SN  - 1613-6810
ER  - 
TY  - JOUR
A1  - Laux, Eva-Maria
A1  - Wenger, Christian
A1  - Bier, Frank Fabian
A1  - Hoelzel, Ralph
T1  - AC electrokinetic immobilization of organic dye molecules
JF  - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry and Analusis
N2  - The application of inhomogeneous AC electric fields for molecular immobilization is a very fast and simple method that does not require any adaptions to the molecule's functional groups or charges. Here, the method is applied to a completely new category of molecules: small organic fluorescence dyes, whose dimensions amount to only 1 nm or even less. The presented setup and the electric field parameters used allow immobilization of dye molecules on the whole electrode surface as opposed to pure dielectrophoretic applications, where molecules are attracted only to regions of high electric field gradients, i.e., to the electrode tips and edges. In addition to dielectrophoresis and AC electrokinetic flow, molecular scale interactions and electrophoresis at short time scales are discussed as further mechanisms leading to migration and immobilization of the molecules.
KW  - AC electrokinetics
KW  - AC electrophoresis
KW  - Molecular dielectrophoresis
KW  - Interdigitated electrodes
KW  - Organic dyes
Y1  - 2020
U6  - https://doi.org/10.1007/s00216-020-02480-4
SN  - 1618-2642
SN  - 1618-2650
VL  - 412
IS  - 16
SP  - 3859
EP  - 3870
PB  - Springer
CY  - Berlin
ER  -