Reliable dose-response and standard curves


Improve Results with Direct Dilution

Prepare dose-response and standard curves using the unique ability of the Echo Liquid Handler to perform Direct Dilution. In a single protocol, the intuitive graphical user interface guides the transfer of samples controls and back-fill solutions for every curve.

Direct Dilution eliminates carryover and improves results

Direct Dilution is a precise method for generating drug concentrations used in dose-response experiments. As opposed to serial dilution, nano- and microliter volumes are transferred in proportion to the desired concentration. With tip-based liquid handling, direct dilution is often not practical or possible. Dilution using the serial method can lead to inaccurate results due to error propagation.

FIGURE: Example of a 11-point curve created using Direct Dilution. The image on top shows how the desired concentrations are created by transfers directly from the stock sample and two intermediate dilutions of the stock sample. The resulting IC50 is shown on the bottom.

Direct Dilution Direct Dilution Direct Dilution25 nL 7.5 nL 250 nL 2.5 nL 10 mM Stock 2.5 nL 30 nL 92.5 nL 100 µM Intermediate 10 nL 2.5 nL 37.5 nL 115 nL 1 µM Intermediate 12.5 nL 5 nL

Assemble dose-response curves by directly transferring different sub-microliter volumes from one or more stock concentrations to achieve the desired final concentration at each point

Acoustic, non-contact transfer with Echo Liquid Handlers eliminates tips, carryover, and dilution errors.

Potency Assays with Direct DilutionPotency AssayswithDirect Dilution%InhibitionInhibitor Concentration (M)1008060402001E-101E-091E-081E-071E-061E-05

Reliable dose-response determination starts with liquid transfers with exceptional accuracy

  • Visualize curve layouts, starting concentrations, final concentrations, and normalization requirements
  • Produce row- and column-wise dilutions
  • Replicate curves in adjacent wells, sequentially or across plates
  • Automate normalization
  • Import a pick list to identify samples for dilution
  • Errors do not compound as in serial dilutions

Echo Dose-Response Specifications

Description Specifications
Operating system Microsoft Windows 7 (32-bit or 64-bit), or Microsoft Windows 10 64-bit (Windows 7 compatibility mode); Windows.Net Framework 4.62 or greater
CPU Intel Core i5 or later
Memory 4 GB or greater
Network connection 10/100/1000 BaseT (2 network connections are required)
Network protocol TCP/IP
Hard drive 4 GB Free Space Available
Video resolution 1920 x 1080 recommended resolution (1440 x 900 minimum resolution)
Echo Client Software 2.6 or later
Echo.Net Framework 1.7 or later