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Image of test tubes and ELISA for article on serial dilution.
Published On: August 10th, 2021

ELISA is based on the interaction of antibodies and antigens where the antibodies attach to specific proteins or nucleic acids. With measurable reporter molecules attached to the antibodies, it is possible to measure the amount of protein or nucleic acid present. Serial dilution ELISA is an important part of testing whenever examining an unknown peptide (or protein molecule) or nucleic acid (or DNA/RNA molecule). For example, testing for SARS-CoV-2, the virus that causes COVID-19, is a major area where rapid testing is crucial.Serial dilution ELISA has to be calculated carefully, or very little useful information will be obtained. For example, when examining an unknown polypeptide, dilutions of 1/2, 1/3,1/5, 1/10, and 1/100 may seem sound. But a dilution from 1/2 and 1/3 is only a 1.5-fold concentration difference, while 1/10 and 1/100 represent a 10-fold difference. Thus, there should be an even difference between every concentration in serial dilution ELISA such as 1/3, 1/9, 1/27, and 1/81 reflecting a 3-fold difference between each dilution.

Automated ELISA Machine

Traditional ELISA procedures require significant time, expensive lab equipment, and expertly-trained technicians to perform. All of these drawbacks have been minimized thanks to automated ELISA machines. These pieces of lab equipment not only save money, space, and time, but they dramatically improve the reproducibility of results by eliminating human error. Automated ELISA machines have been around for years, and they have proven themselves invaluable in modern life science and pharmaceutical labs.

An area where they excel is when performing serial dilution ELISAs. As the second paragraph (above) showed, calculating serial dilutions can be challenging, but creating those dilutions without significant error is nearly impossible, especially when the dilutions are 1/96 or even 1/288. Nothing beats a fully automated ELISA machine for performing serial dilution ELISA accurately, reliably, quickly, and inexpensively.

Another feature of ELISA automation is found in the automated ELISA readers. These machines perform all of the analysis using a spectrophotometer that reads each well’s color reaction product and optical density. Many of the fully automated ELISA readers will also plot the sample results against the curve from the serial dilution ELISA standard.

Microplate Washer ELISA

When performing an ELISA, manually or with an automated ELISA machine, multiple steps require washing the microplate wells. When done by a technician, it can be difficult to do carefully enough not to disturb the reactions taking place in each well. In addition, the amount of buffer solution should be as precise along with the time each well is washed. It is not difficult to imagine significant variations in these factors during several wash cycles leading to unreliable and inaccurate results. An ELISA plate washer is the answer.

With an automated ELISA plate washer, variability is eliminated as the microplate washer uses precise timing and buffer quantities in every well. Eliminating the variability that comes with a technician would be even more critical when performing serial dilution ELISA. The ultimate goal remains to perform experiments rapidly, inexpensively, but with reliability and accuracy to ensure excellent reproducibility. Serial dilution ELISA effectively requires the use of automation in modern laboratories.

ELISA and Hudson Robotics

When the laboratory performs serial dilution ELISAs daily or only once a week, any modern laboratory requires automation, including a fully automated ELISA reader. The initial investment is not as high as most researchers think, and the benefits are numerous. With an automated ELISA platform in a laboratory, the benefits include:

  • Fewer costs for equipment and supplies.
  • More time to focus on reviewing experimental results, drafting journal submissions and reports, and preparing future experiments.
  • Less exposure of dangerous chemical reagents to personnel.
  • Significantly greater accuracy, reliability, and reproducibility in every experiment including complicated serial dilution ELISAs.
  • Financial savings on personnel, equipment repairs, reagent purchases, and especially on disposable supplies. (Consumables such as culture dishes, tips, pipette tubes, etc. make up over half of most life science laboratories’ budgets.)

Of course, there are many more benefits to laboratory automation that other blogs discuss. However, when performing serial dilution ELISA and needing the best results for the lowest operating costs, there is only one place to turn. Hudson Robotics are specialists in laboratory automation since 1983. Contact them today to discuss all of the options for automated serial dilution ELISA or any other laboratory automation need.