Genomic DNA was isolated from Arabidopsis thaliana according to Edwards et al. (1991). DNA fragments of different lengths were produced by artificial polymerase chain reaction (PCR) using biotinylated forward primer (5‘ TCA ACC AAA TCC AAA TTC TAC ACA T 3‘) and Atto520 labelled reverse primer 340 bp: 5’ ATA GGT ACG CGG AGC AAC AT 3’, 500 bp 5’ TCG AAA GAA ATC GTT GAA GC 3’, 722 bp: 5’ CCA TTC TGT TAT GGC GGA AGA ACA C 3’, 2000 bp: 5’ TCT ACT TCC ACA TCC ATT CTT TC 3’) with genomic DNA as template. The PCR reaction products were separated by agarose gel electrophoresis and the PCR product was isolated from the gel to remove excess primer oligonucleotides (Nucleo Spin® Gel and PCR Clean Up System, Machery Nagel). The DNA concentration was determined with the NanoPhotometer® N60/N50 (Implen).

Biotinylated DNA was coupled to streptavidin-coated 300 nm  magnetic particles from Ademtech Pessac, France according to manufacturer’s instructions. Briefly, 10 µl magnetic particles (5 mg/ml) were washed twice with immobilization buffer (pH 7). 2 µg modified DNA suspended in a total volume of 10 µl was added to the magnetic particles and gently shaken in an overhead rotator for 30 min at room temperature. Particles were washed three times with immobilisation buffer and finally resuspended in destilled water to a final concentration of 1ng particles per µl solution.

Suspensions of DNA-functionalized particles (and bare particles for control) were pipetted into wells of a microtiter plate. These wells were placed below an optical brightfield microscope. Particles that moved freely, i.e., far away from the well's walls, were placed in the focal plane of the microscope. Videos of 120 s duration were recorded for each particle sort (different DNA length), with a frame rate of 60 frames per second and at an image resolution of 2048 px x 1536 px using a high-resolution camera (DMK 33UX265 with Sony IMX265 sensor).

The respective .rar files contain a .avi video file. The file name describes the length of the DNA. The experiments were performed three times, which is described by the last digit of the file name. 

For viewing the Videos, it is recommended to open the .avi files with VLC media player. A warning may appear when opening the files stating that the index is broken or missing. Selecting the option "Play as is" plays the video without further problems.