Protein Interaction Coupling Technology
Actome's propiarety Protein Interaction Coupling Technology, or short PICO, allows you to detect and quantify proteins, protein interactions and post-translational modifications with ultra-high sensitivity. With our kits you are able to label antibodies, that you are free to choose, conduct a PICO assay and analyze the results with our free, online based AMULATOR software. Read our PICO Handbook for an comprehensive overview.
The unique features of PICO are:
- Ultra-high sensitivity (upper femtomolar with ordinary antibodies)
- Zero background
- Small sample input (down to 0.5 µL or a couple of 100s of cells)
- Absolute quantification (quantifying molar amounts with no external standard)
- Easy multiplexing (up to four antibodies)
- Digital assay (counting molecules)
- Homogeneous (measuring in non-denaturing conditions without washing steps)
Watch our technology explainer video first to learn about the PICO principle:
The PICO Workflow
Antibody selection & labeling
After selection of appropriate antibodies against the target, the antibodies (I) are conjugated with Actomidin (II). PICO DNA Labels are loaded onto the antibodies to form ready-to-use binding agents (III) for the PICO assay.
Cell lysis & incubation
The cells are lysed (I) and then incubated (II) with two different antibodies that have been selected and labeled before.
Couplex formation during incubation
The biological environment allows the targets to retain their interactions (I). Two different antibodies bound to the same target are called ‘couplex‘ (II).
Sample dilution
The sample is highly diluted (I) and loaded onto a QIAcuity Nanoplate (II). The high dilution ensures a maximum of one molecule per compartment (III).
Digital PCR
The dPCR is carried out on the QIAcuity digital PCR System (I) using QIAGEN‘s dPCR consumables and assay kits. Thousands of compartments are simultaneously amplified (II) and compertments containing ‘couplexes‘ are counted (III).
Analysis with AMULATOR software
The dPCR raw data is exported from the QIAcuity and uploaded to Actome‘s AMULATOR software. The cloud-based software provides the user with comprehensive results regarding the targeted proteins or protein interactions.
What can be a PICO target?
By using a 2-plex setup (two labeled antibodies) you are able to detect and quantify:
- I. Single proteins (by using two antibodies targeting different accessible epitopes of the same protein)
- II. Post-translational modification (by using one antibody targeting the protein and one antibody targeting the PTM)
- III. Protein interactions (by using two antibodies, each targeting one of the interacting proteins)
- IV. Combinations of all of the above (e.g. protein interaction upon PTM)
By using a 4-plex setup (four labeled antibodies) you are able to detect and quantify simultaneously:
- I. Two individual singe proteins (by using two antibodies per protein)
- II. Two individual interactions (by using two antibodies per each interaction)
- III. One interaction and one single protein (by using two antibodies for the interaction and two antibodies targeting the single protein)
- IV. 'Quadratic measurement' - allowing to quantify an interaction and both interaction partners (by using two antibodies for each interacting protein)
- V. 'Triangular measurement' - e.g. quantify the total amount of a protein and simultaneously quantifying the ratio of a PTM (by using three antibodies for one target)