Questions and answers

chromnil GmbH is a Swiss startup from Zurich making high-performance thin-layer chromatography (HPTLC) faster, simpler and more affordable. It builds chromnil one, a compact benchtop instrument for HPTLC with effect-directed analysis. chromnil one runs all five HPTLC steps in one connected system, so a lab can see which compounds a sample contains and which of them are biologically active.

High-performance thin-layer chromatography (HPTLC) is a separation method in which the compounds of a sample are separated on a plate coated with a thin, fine-grained stationary phase such as silica gel. A solvent moves up the plate and carries each compound to a characteristic height, its R_F value. Many samples run side by side on one plate, under identical conditions, and every zone stays accessible for detection.

Effect-directed analysis combines a chemical separation with a biological test. After HPTLC, a bioassay (for example enzymes, bacteria or cells) is applied directly to the plate, and only the zones that trigger or inhibit the biological response become visible. This planar bioassay shows not only which compounds a sample contains, but which of them have an effect, including compounds nobody was looking for.

chromnil one runs five steps on one 10 × 10 cm HPTLC plate: application of the samples as narrow bands, development with about 2 mL of mobile phase, the bioassay (a test system sprayed over the plate and incubated), an optional derivatization with a reagent mist, and detection with a 12 MP camera after each stage. All five steps are controlled from a single program. The technical overview shows each step.

chromnil one analyses samples from food and environmental analysis, cosmetics, pharmaceuticals, forensics and research: anything that can be dissolved and applied to an HPTLC plate. Typical questions are which compounds a sample contains, which of them are biologically active, and whether a product is authentic.

Depending on the bioassay, chromnil one shows antibacterial, genotoxic, enzyme-inhibiting, hormone-like or cytotoxic zones; chemical assays such as radical scavenging run the same way. Any test system that can be sprayed as a liquid can be used: it is applied directly to the developed plate and incubated in the connected incubator at 30–37 °C for a set time. Active zones stand out from the background: bright in fluorescence assays, dark where luminous bacteria are inhibited, pale where an enzyme is blocked.

chromnil one runs the planar bioassays published for the 2LabsToGo systems: the bioluminescence assay with Aliivibrio fischeri for antibacterial and cytotoxic compounds, the planar yeast estrogen screen for hormone-like compounds, the SOS-Umu-C assay and the planar Ames test for genotoxic and mutagenic compounds, and enzyme inhibition assays such as acetylcholinesterase or tyrosinase. These assays use the organisms and endpoints of standardised water tests (ISO 11348-3, ISO 19040-1, ISO 13829, OECD TG 471); the strains come from culture collections and are grown in the lab as for the standard tests. Any other test system that can be sprayed as a liquid can be used too.

Yes. A bioassay responds to what a compound does, not to what it is, so chromnil one also finds active compounds that no target list includes, for example unexpected contaminants in food or cosmetics. Each active zone appears at its own R_F value on the plate, next to the standards run under the same conditions.

Up to 9 samples plus standards, side by side on one 10 × 10 cm plate and under identical conditions. The rack takes vials with 1–2 mL each, either reusable glass or single-use plastic.

It depends on the method. Applying a full plate takes about ten minutes, development typically 10 to 20 minutes depending on the migration distance, and imaging a few seconds per light. A bioassay adds its incubation: a few minutes for enzyme assays, about three hours for cell-based assays such as the yeast estrogen screen, often followed by a substrate and a second incubation of about 30 minutes. All samples on the plate run through these steps together, so the time per sample is a fraction of the time per plate.

Very little. Each plate is used once, so the sample matrix stays on the plate and does not harm the system. A plate takes about 2 mL of mobile phase, and the applicator uses about 1.5 mL of rinsing solvent per sample.

A 12 MP camera images the whole plate under UV (365 and 265 nm), visible and white back light. Each track becomes a densitogram, and zones are integrated and quantified against standards on the same plate. The published benchmark data were evaluated with the open-source software quanTLC, which chromnil one uses as a separate step today; its integration into the chromnil software is planned. Read more in Data evaluation.

Yes. In a peer-reviewed study on ergot alkaloids in whole rye (Jakob et al., Food Chemistry 453, 2024), the 2LabsToGo system that chromnil is based on reached a repeatability of 4.1% RSD (status quo HPTLC 4.8%) and a linearity of R² 0.9918 (status quo 0.9890). With two planar bioassays on the plate, the 2LabsToGo-Eco, the hardware generation chromnil one is developed from, reached 2.5–6.0% RSD and R² 0.9921–0.9982, comparable to about ten commercial devices (Romero et al., Analytica Chimica Acta 1367, 2025). The technology page explains the method and the full figures.

2LabsToGo-Eco is an open-source instrument for HPTLC with planar bioassays from Prof. Gertrud Morlock's group at Justus Liebig University Giessen, the result of 15 years of academic development, and chromnil one is developed from it. The academic system has to be built, calibrated, repaired and updated by its users. chromnil one turns this research into an instrument for routine laboratory work: chromnil's own engineering makes it more robust and easier to use, and every system arrives assembled, configured and calibrated, with regular software updates, service, training and continuous support.

The 2LabsToGo-Eco that chromnil one is developed from is open source: its hardware is published under the CERN Open Hardware Licence and its software and firmware under the GPL v3, on GitHub (opens in new tab). chromnil one builds on that base with chromnil's own engineering. Ask us about the licensing of the chromnil software itself.

The chromnil one instrument measures 26 × 41 × 36 cm, about 0.1 m² of bench space; the connected nebulizer and incubator modules need their own space beside it. All five steps are controlled from a single program on a connected computer.

Standard 10 × 10 cm HPTLC plates, which the user supplies: usually a 20 × 10 cm HPTLC silica gel plate cut in two. Other plate types of the same size work as well. The number of tracks per plate depends on the band width; the rack holds up to 9 samples.

Standard 10 × 10 cm HPTLC plates (one per run, used once), vials of 1–2 mL, about 2 mL of mobile phase per plate and about 1.5 mL of rinsing solvent per sample, and, for a bioassay, the test organisms or enzymes with their media and substrates, as for the standard tests they are based on. Derivatization reagents are optional. No columns, carrier gas or pumps wear out; the solvents and reagents are the same as in any HPTLC lab and can be sourced from the usual suppliers.

Yes, in most cases. chromnil one uses standard HPTLC plates and stationary phases, and the mobile phase and detection settings of a method stay the same. The instrument doses the mobile phase itself, so the solvent volume and the migration distance are set in the software. In the published comparison, the same ergot alkaloid method ran on the 2LabsToGo and on conventional instruments with the same mobile phase and gave comparable results (Jakob et al., Food Chemistry 453, 2024).

chromnil one is controlled from a connected computer over Ethernet or Wi-Fi and does not need an internet connection. The plate images can be exported in standard image formats. Quantification runs in the open-source software quanTLC today; its integration into the chromnil software is planned.

The assembled system, configured to your needs; regular software updates; service if the system malfunctions or gets damaged; and training and continuous support.

chromnil one is planned for 2027. Prices are quoted on request: contact us for a quote and the current timeline.