Sequential Dispensing – Serial Dilutions Made Easy

You know that serial dilutions are one of the most tedious routine tasks in the laboratory. Because you know that it usually requires pipetting of individual volumes. And individual volumes necessitate repetitive volume setting. An electronic pipette offers an excellent solution: with its sequential pipetting mode, you can dispense individual volumes in sequential order in just one go! Applications like dilution series become significantly easier and you save valuable time.

Double work with serial dilutions


Pipetting of individual volumes sequentially like serial dilution of nucleic acids, cells, proteins, antibiotics, and other substances like dyes, buffers or reagents belong to the routine applications in the lab. The application spectrum is widespread ranging from preparation of standard curves, photometric DNA quantification, or Bradford protein quantification to the creation of sample stocks.


Taking a closer look at the serial dilution technique, one quickly concludes that it is repetitive and time-consuming. In the worst case, the mechanical pipette has to be adjusted to the desired volumes after each step - and several times in a row. In short, there are four hassles:

  1. Double work: A series of only 5 concentrations requires readjusting the volume 10 times.
  2. Many arm movements due to repeated liquid aspiration and dispensing – from reagent to tube, and vice versa.
  3. Repetitive refocusing to continue at the right row/column for liquid dispensing.
  4. Impairment of precision due to the normal irregularities like user-dependent thumb speed or varying operation forces. Being essential for dilution series, precision is dependent on pipetting uniformly over each step.


Up to 10 individual volumes in one go


If you want to save time and prefer not to work at the expense of precision when performing serial dilutions, sequential dispensing with an electronic pipette is a solution. Sequential dispensing means to aspirate once and dispense up to 10 user-defined volumes in sequential order in one go. This means, up to 10 times less work compared to mechanic pipetting!


How it works:

1. Adjust

Choose the number of pipetting steps and the respective volumes in the sequential dispensing mode

2. Pipette liquid #1

Aspirate the entire volume of liquid #1 only once.

Dispense the preset individual volumes in several vessels sequentially one after the other without aspirating again.

3. Pipette liquid #2

Aspirate the entire volume of liquid #2 only once.

Dispense in opposite direction (reverse vessel order) sequentially without aspirating again.

Pipetting in defined volumes during serial dilutions
Preparation of serial dilution with an electronic pipette


Quick and hassle-free serial dilutions


Your benefits from sequential dispensing with an electronic pipette:

  • Time-saving

Firstly, you do not have to readjust the pipette to the respective volume after each step. Secondly, you do not have to aspirate liquid again after each pipetting step. This increases your working speed, you finish faster and save time.

  • Hassle-free serial dilution

Your focus does not have to switch alternately between the liquid or sample and the target vessels. During dispensing you can keep your focus on the vessel and you don't have to think about where to go on. You can concentrate much better and make fewer mistakes.

  • High accuracy and user-independent reproducibility

Uniform pipetting with an electronic pipette without user-dependent fluctuations increases accuracy and reproducibility and thus the reliability of results when using this serial dilution method

  • Super easy application

The intuitive operation and selection of the desired parameters allow you to get started immediately.


If you already have an electronic pipette, then dare to simply try out the many useful functions like reverse pipetting, multi-aspiration, automatic dispensing, and many more. If not, ensure to select an intuitive and easy to use electronic pipette model.


Visit Eppendorf’s handling solutions site regularly to find out more.