ONCYTE® Film slides


ONCYTE ® Porous nitrocellulose Film slides are comprised of a microporous nitrocellulose film cast on a variety of solid surfaces. They offer numerous advantages over functionalized  surface chemistries:

  • An increased available surface translates into high protein binding capacity.
  • Fluorescence Signal Amplification via the Tyndall effect for enhanced sensitivity.
  • Broad dynamic range and low detection limit

SEM image of ONCYTE® Porous nitrocellulose film. The small pore supplies a very large surface
area which contributes to its high binding capacity. The pore structures in this formulation promote controlled and uniform wetting, thus making it ideal for microarray deposition.

Tyndal Effect. When excitation light strikes the surface of the PNC, tiny voids in the film scatter the incident light, causing many of the photons to reflect back onto fluorophores, thus increasing the probability that the excitation light will be absorbed by a fluorophore. Thus the effective “extinction coefficient” is greatly increased.

Detection of Antibody Binding Capacity on Blocked Substrates. Data represent mean fluorescent intensities from serial dilutions of IgG-TRITC spotted in duplicates on multiple array slides (n=4) after extensive washing and detected with 532 nm excitation. Biotechniques: 2013 Vol 54, No 4: pg 223-225

ONCYTE® film slides are manufactured to the highest standards and quality tested, they provide excellent reliability and reproducible. There are many existing pad configurations available, and Grace has the ability to customize film patterns to meet the needs of customers. In addition, Grace offers strong R&D support for new applications and quality support for variance control of key performance indicators.

Protein Microarray Substrates Selection Guide

enlarge table


Oncyte® Brand Nitrocellulose Thin Film Slides

Nitrocellulose Film*





Binding capacity

Film thickness

12 µm

7 µm

12 µm

< 200 nm

Dynamic Range
(log scale fluorescence)





(contact angle)





Preferred Detection
Methods 2






Antigen or antibody binding, cell or tissue lysate binding, glycoprotein and peptide binding assays

Antigen or antibody binding, glycoprotein and peptide binding assays

Antigen or antibody binding cell or tissue lysate binding glycoprotein and peptide binding assay

Antigen or antibody binding, glycoprotein and peptide binding assays

*   Exclusively from Grace Bio-Labs
1   More hydrophobic surfaces may result in reduced spot diameter, depending on the spotting buffer composition. Results may vary based on buffers, sample preparation, spotting and scanning instruments. See our ONCYTE® user guide for full discussion.
2   All detection methods are compatible with ONCYTE® Nitrocellulose Film Slides.


Reverse Phase Protein Arrays

ONCYTE Film Slide Overview

2013 Microarray World Congress Presentation By Grace Bio-Labs



de Assis, Rafael R et al. “Analysis of SARS-CoV-2 antibodies in COVID-19 convalescent blood using a coronavirus antigen microarray.” Nature communications vol. 12,1 6. 4 Jan. 2021 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7782488/)

Herrera NG, Morano NC, Celikgil A, et al. Characterization of the SARS-CoV-2 S Protein: Biophysical, Biochemical, Structural, and Antigenic Analysis. ACS Omega.  Dec 21, 2020 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7771249/).

Byron A, et al. Integrative analysis of multi-platform reverse-phase protein array data for the pharmacodynamic assessment of response to targeted therapies. Sci Rep. Dec 15, 2020 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7738515/). 

Vo HTM, et al. Autoantibody Profiling in Plasma of Dengue Virus-Infected Individuals. Pathogens. Dec 18, 2020  (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766539/).

See more references for ONCYTE Film slides here


Q. Which concentrations of antibodies or proteins should be printed on the ONCYTE® Film Slides?

A. For purified proteins a concentration of about 0.05-1 mg/ml is optimal for most applications, the upper end of this range is recommended for antibodies.

Q. Should printing be performed at low temperatures?

A. No, printing may be performed at room temperature as long as humidity is maintained at around 50-55% to avoid sample evaporation during the process.

Q. My protein sample contains urea, is this going to affect protein binding to ONCYTE® Film Slides?

A. No. Samples containing urea are routinely printed on ONCYTE® Film Slides. Slides are chemically resistant to reagents typically used in most assays for cell analysis including 50% formamide. Film slides are not recommended for use with acetone, ethanol, and methanol. Isopropanol and butanol are common substitutes. DMSO could negatively affect nitrocellulose too, therefore its concentration should not exceed 5%.

Q. Can traditional western blot blocking buffers be used for blocking protein microarrays?

A. The composition of the blocking buffer should be optimized for each experimental setting. Colorimetric and chemiluminescent detections are compatible with the blocking buffers commonly used for western blot, such as PBS or TBS containing 1-5% non-fat milk. Fluorescent detection, on the other hand, can be hampered by background fluorescence typically associated with protein–based blocking buffers. Super G Protein array blocking buffer has been optimized for fluorescent assays and produces a very high signal to noise ratio, minimizing the background fluorescence.

Q. How do I image my microarray results?

A. ONCYTE® Film Slides are compatible virtually with all detection systems: isotopic, chemiluminescent, chromogenic, and fluorescent detections are all viable options.

Q. How should printed ONCYTE® Film Slides be stored?

A. Non-printed slides should be stored at room temperature in their original packaging. Printed slides can be stored at 4°C for short-term storage or at -20°C for long-term storage. An overnight incubation at 4°C is recommended after printing in order to maximize protein binding before use.

Q. What kind of controls should be included in the microarray analysis?

A. IgG pre-labeled with a fluorophore should be spotted on the array to check for proper protein binding. Buffer-only spots can be used for background subtraction, as well as secondary antibody-only stained film slides. Replicates should also be spotted on the array for each protein.

Q. Can ONCYTE® Film Slides be ‘stripped’ and re-used?

A. No. It is not advisable to re-use ONCYTE® Film Slides.