Data included in the publication "Plasma Polymerisation Using Helium Atmospheric-Pressure Plasma Jet with Heptylamine Monomer" piublished in Plasma Processes and POlymers Data are in folders titled after the main experimental sections: Contact angle, XPS, AFM and cell culture. There are 4 different sample types that are referred to (note that every sample type was not used in every experiment): Untreated polystyrene (UT-PS or UT) POlystyrene treated with helium plasma (Helium or He) POlystyrene treated with helium plasma containing heptylamine (Heptylamine or Heptyl) Tissue culture treated polystyrene (TCPS or TC) Each folder contains an Excel spreadsheet containing values extracted from raw data and the average +/- standard deviataions. Were applicable the data is also contained in a .sav file, with assoicated .spv which can be opened in SPSS; which is the software in which statistical analysis was conducted. AFM - raw data is in a file type which can be opened by Bruker AFM software.The suffice on the file names e.g. FILENAME_3.001 refers to sample number and scan number on that samples res XPS - raw data is available in .txt and ".1" file type. XPS was analysed in CasaXPS and .vms and .FIT files are present which should contain the curve fitted data.The spatially resolved spectra are in folders named after the sample, the file names contain positions e.g. 9.25mm, 10.25mm which refer to the position of the movable stage on which samples were mounted. Contact Angle - within each sample folder are dated folders. These dates refer to the 2 repeats. File names are 27.0, 27.5, 28.0 etc which refer to the x-position of the movalbe stage on the contact angle system and increase in 0.5mm. Raw data are .AVI. Data were calculated with DSA3 software by Kruss. The contact angle of the first resolvable frame was used and subsequent frames were ignored. Cell culture - Data contained in folders titled "Polymerisation" and "Polymerisation 2", which refer to the 2 repeats of the experiment. raw data is available in .zvi, which is a Zeiss proprietary file and can be opened by various image analysis software. ImageJ was used in this study. File names are arranged "Date captured_Culture Day_Sample Type-Sample Number_Experiment Type_xposition_yposition" E.g.2013-01-06 D4 He-2 Counts 1.5_0 = Helium treatment, sample number 2, cultured for 4 days, cell counts experiment, image at position x=1.5mm y=0mm Cell culture "montage" data refers to the stitched images used to calculate the area of growth. File names are similar to the counts data X and Y refer to the axis on which the image was taken. X1,X2, X3 etc refer to the sequence in which images were taken across the sample. .JPG ending with either X or Y are completed stitched images.