Microplates: An Overview


A microplate or microtiter plate or microwell plate, is a flat plate with multiple “wells” which are used as small test tubes. The microplate has become a standard consumable tool in analytical research, drug discovery programmes, research laboratories, clinical and diagnostic testing laboratories. A very common use is the enzyme-linked immunosorbent assay (ELISA) which has become the backbone of most modern medical diagnostic testing for humans and animals. A number of factors affect the accuracy and reliability of the results obtained from microplate based assays. The company’s focus is to either minimise or eliminate microplate handling and maintenance issues which effect assay quality and outputs during both manual and automated processing of microplates. By achieving this, Oxley Hughes enables microplate users obtain a higher level of accuracy and precision. This improvement in microplate consistency due to reduced variability enables people to concentrate on what is important to them: their work and their science.

Common sources of microplate assays and outputs variabilities include:– damaging the science such as cell monolayers in the microplate wells during aspiration and dispensing steps; leaving residual amounts of solution (or carry over) which can effect subsequent stages in microplate processing and readings; scraping and damaging well contents with pipette tips; reversing microplates and banging out remaining solutions; cross contamination; poor seeding of microplates with the scientific material of interest; blockage of pipette tips or manifold pins leading to increases in full equipment maintenance; and, pins from manifolds contacting and scraping the science as well as variable amounts of residual solutions left in the wells due to the natural curvature of microplates. All of these common microplate handling and maintenance issues cause variation which effect both the accuracy and quality of microplate assays and outputs.

How is microplate quality measured?

The quality of microplate based assays can be determined using Z’-prime, Z-factor and the percentage coefficient of variation (%CV) [1]. These calculations use standard deviation and assay signal-to-baseline ratios to measure overall assay quality. A more consistent microplate assay with reduced variability will be statistically viable and robust; it will increase confidence in outputs; reduce the amount of repeats as well as workload; and, will reduce the amount of plastic consumables used. Oxley Hughes’ technology improves these mathematical statistical measures of microplate assay quality through its improved microplate handling and maintenance technology while also improving specific aspects of operator safety.

Oxley Hughes has 6 primary aims for you, our customer. They are:

  • Improve the accuracy and precision of your microplate based assays and outputs.

  • Increase your confidence in your microplate based work so minimising the number of repeats you have to carry out which in turn reduces your workload, costs and plastic wastage.

  • Make your time handling and maintaining microplates easier and simpler.

  • Decrease microplate variability while simultaneously increasing microplate consistency for you.

  • Enable you to focus on what is important to you: your work and your science.

  • Ensure all of this is achieved cost effectively for you.

How can microplate assay quality and outputs be improved?

This is achieved by addressing aspects of microplate handling and maintenance which affect assay consistency and cause variability in and between microplates;

  • a reduction in well-to-well variation;

  • maximised signal-to-baseline ratios;

  • improved sample treatment during microplate preparation;

  • ensure the integrity of the science present in the microplate wells;greater accuracy and precision in liquid handling and solution exchanges.

Any improvements in the above will be demonstrated by increases assay consistency, confidence, reproducibility, reduced processing times, a reduction in the number of repeats leading to a reduction in costs of these consumables and increased operator safety for microplate based assays. Oxley Hughes has addressed all of these resulting in the optimal microplate solution for you.

How do we achieve these improvements for your microplate assays and outputs?

Oxley Hughes achieves the above by a simple yet elegant and effective system of microplate modifications and microplate handling accessory which guide pipette tip points to a specific contact and fixing point located in the base of each microplate well. Oxley Hughes’ modified microplates can be used manually or in automated microplate washers. To obtain the full benefits of the technology, Oxley Hughes’ modified microplates are used with the Oxley Hughes microplate holder. This ensures the pipette or aspiration tip contact and fixing point occupies the lowest point of each well during microplate handling and maintenance. Only when placed in an Oxley Hughes holder are Oxley Hughes microplates inclined so they are read just like a standard microplate in existing microplate readers.

Oxley Hughes microplates are only inclined when place in the microplate holder for solution exchange.

Oxley Hughes’ microplates are compatible with your existing automated microplate washers and equipment so if you need to process large numbers of microplates, you can use our microplates so your work and science will still benefit from nearly all of the technology’s microplate improvements.