Measuring pH in a sample that contains proteins, sulphides, thiols, tris, or vitamins can often present difficulties if the correct electrode is not used. There are a vast number of applications that fall into this category ranging from pH measurements in nutrient agar through measurements in mammalian blood, to low ionic strength samples.

Standard pH electrodes have a silver/silver chloride reference which necessitates silver ions in solution.

These silver ions can react with many species found in a life science laboratory forming insoluble salts or complexes resulting in blockage of the junction leading to unstable and inaccurate readings and finally total electrode failure. Traditionally a calomel based electrode would be used, however these mercury containing electrodes present potential disposal problems.

Thermo Electron have addressed the needs of the biochemical world by creating the new Bio-K electrodes. Bio-K electrodes incorporate patented technology using a fully substituted, cross-linked polymer as the elemental reference electrolyte. Each is supplied complete with a cleaning solution for the pH glass membrane.



The unique reference material is exceptionally stable resulting in minimal drift, fast speed of response and improved accuracy. Consequently there is not the same requirement for frequent re-calibration to obtain highly accurate results.
The Bio-K range consists of a standard size glass electrode, a semi-micro glass electrode for NMR tubes or small samples and, a standard size plastic electrode for increased robustness, ideal for student use. The specifications for these can be seen above.

Thermo Electron manufactures and supplies all electrodes with 1m cable terminating in BNC. Should other termination or dimensional variation be required please do not hesitate to contact us on 01337 828871 and our technical team will be able to answer your questions.