In modern life science research and clinical testing, automatic washing machines have become the core equipment in experimental processes such as enzyme-linked immunosorbent assay (ELISA), cell culture, and high-throughput screening. Its core function is to efficiently, accurately, and without cross contamination clean unbound substances in the microplate, thereby ensuring the accuracy and repeatability of subsequent detection signals. However, many users mistakenly believe that "washing the board is just a simple liquid injection+suction", in fact, different types of experiments have completely different requirements for cleaning methods.
Automatic washing machines typically offer multiple cleaning modes to adapt to diverse application scenarios.
1、 Standard cleaning mode
This is a basic and widely used pattern suitable for routine ELISA experiments.
Workflow: Inject a set volume of cleaning solution into each hole → briefly soak → aspirate waste liquid → optional "tapping" (assisted by mechanical vibration or airflow for drainage).
Features: Fast speed, simple operation, suitable for removing free antibodies, antigens, or enzyme-linked secondary antibodies.
Attention: The suction height should be precisely adjusted to avoid damaging the bottom of the board or leaving too much liquid.
Applicable scenarios: Routine immunological analysis such as infectious disease serological testing and hormone quantification.
2、 Overflow cleaning mode
This mode injects a washing solution that exceeds the pore capacity, causing the liquid to overflow from the orifice and flush the pore wall.
Workflow: Inject a large amount of washing solution → The liquid naturally overflows → Absorb the waste liquid.
Advantage: Effectively removes non-specific binding substances attached to the pore wall and significantly reduces background signals.
Application scenarios: high-sensitivity ELISA, low abundance target detection, or serum/plasma detection with complex sample matrices.
3、 Bottom flushing mode
Specially designed for cleaning adherent cells, avoiding cell shedding caused by traditional top suction.
Workflow: The washing solution is injected from the top of the hole, and the suction needle slowly descends to near the bottom of the hole (but does not touch), and the waste liquid is sucked out with extremely low negative pressure.
Key parameters: Adjustable suction height and gentle suction speed.
Supporting function: often linked with the "cell protection mode" to limit the impact force of injection.
Applicable scenarios: Cell ELISA, pre staining cleaning of immune cells, stem cell or primary cell processing.
4、 Immersion cleaning mode
By prolonging the residence time of the washing solution in the well, the dissociation effect on stubborn binding substances is enhanced.
Workflow: Inject liquid → Allow to soak → Absorb liquid.
Programmable combination: Some models support "multi round soaking+suction" cycle.
Attention: Prolonged soaking may cause the dissociation of some unstable antigen antibody complexes, and experimental compatibility needs to be verified.
Applicable scenarios: high affinity complex cleaning, removal of fat soluble impurities, or strong non-specific adsorption of samples (such as tissue lysate).
5、 Multi point cleaning mode
Perform multiple injection suction cycles within a single well to improve cleaning efficiency.
Example: One program completes two rounds of operations: "liquid injection → liquid suction → re injection → re suction".
Advantages: More water-saving than single large volume cleaning, and lower residual liquid.
Application: Chemiluminescence (CLIA) or fluorescence detection sensitive to residues.
6、 Area selection cleaning
Not all holes require cleaning, this mode allows cleaning only specified rows, columns, or any hole position.
Operation method: Select the target hole through the software, and the instrument will skip other holes.
Value: saves reagents, reduces waste liquid, suitable for experimental designs such as gradient dilution and control well retention.
Applicable scenarios: drug dose-response curves, standard dilution plates, mixed sample plates.
7、 Disinfection/maintenance cleaning mode
Used for cleaning and disinfecting the equipment's own pipelines, not for sample cleaning.
Function: Rinse the entire liquid pathway with deionized water, ethanol, or sodium hypochlorite solution.
Trigger timing: before and after daily use, when changing the type of washing solution, or before long-term shutdown.
Importance: Prevent protein deposition, salt crystallization, or microbial growth from blocking the pipeline.
Conclusion
The "intelligence" of automatic washing machines is not only reflected in the degree of automation, but also in the refined cleaning strategies provided for different biological problems. Choosing the correct cleaning mode can not only improve data quality, but also extend the lifespan of consumables and reduce experimental costs.