New Algorithm for Splicing Detection
Imagetwin now detects splicing seams in gel band images, such as western blots. A western blot consists of several lanes, whereas the procedure of removing, inserting, or re-assembling individual lanes is known as splicing. Splicing is not necessarily inappropriate behaviour, especially when declared. However, in some cases, splicing is used to manipulate the original image data, and it is critical to detect these cases. The splicing detection is accessible through our web application and the API, helping you to identify splicing seams quickly and effectively.
Forensics toolbar
Whenever a gel band image is input into our software, the image is screened for potential splicing seams. Findings are then presented in the web application with a score indicating how confident our machine learning model is in their prediction. A finding can be further investigated in the detail view using the new forensics toolbar. The forensics toolbar allows for altering the image, such as changing the brightness or the contrast. This helps to improve the visibility of details that are difficult to see by eye. The forensics toolbar might also be useful for other findings, such as improving visualizations of duplicates.
Detection accuracy
We evaluated the splicing detection algorithm in terms of accuracy and false positives. To measure accuracy, we tested the algorithm on 157 spliced western blots recently posted on PubPeer. The software correctly identified and located the splicing seams in 127 of the 157 images (81% accuracy). To measure the false positive rate, we applied the algorithm to 500 western blots randomly sampled from papers published from 2010 to 2023. In total, 15 of the 500 images were flagged, which we further analyzed. Of the 15 flagged images, 7 were actually spliced, 2 were incorrectly flagged as spliced, and 6 were low-quality images difficult to assess because of pixelated areas and compression artefacts (e.g., JPG).
| Data | Number of western blots |
|---|---|
| Spliced western blots sampled from PubPeer | 157 |
| Western blots sampled from publications from 2010 to 2023 | 500 |
Frequently asked questions
How do I tell if a Western blot has been spliced?
Imagetwin’s splicing detection algorithm identifies seams in gel band images where lanes have been removed, inserted, or reassembled. Detection was validated on 157 spliced Western blots from PubPeer, correctly identifying splicing seams in 127 cases (81% accuracy), with only 2 false positives in 500 randomly sampled Western blots. Results include a confidence score and a forensics toolbar that lets editors adjust brightness and contrast to investigate suspicious regions in detail. Splicing detection is available via both the web application and API.
What are the most common ways figures get manipulated in Western blots specifically?
The three most frequently detected manipulation types in Western blots are vertical splicing (removing or inserting lanes), horizontal splicing (cutting and rejoining bands across rows), and copy-paste forgeries (cloning regions within or across images). Splicing is not always inappropriate when declared, but undeclared splicing used to misrepresent experimental results is one of the most common integrity violations flagged on PubPeer. Imagetwin detects all three types under a unified manipulation detection framework, with an overall false positive rate of 1.7% and 81% accuracy on splicing detection specifically.
Is Imagetwin or Proofig better for Western blot splicing detection?
Imagetwin’s splicing detection achieves 81% accuracy on 157 confirmed PubPeer cases, with 2 false positives in 500 randomly sampled Western blots. Its broader manipulation detection model covers vertical splices, horizontal splices, and copy-paste forgeries with a 1.7% false positive rate overall, and 90% accuracy on duplicate detection specifically. Results include a forensics toolbar for manual investigation. Proofig is also used for Western blot analysis, although the accuracy is not determined; Imagetwin differentiates on published accuracy figures, cross-publication detection against 160M+ images, and per-paper pricing.
