GL Sciences has been manufacturing extremely pure Titanium Dioxide microparticles for many years, and has recently introduced the most efficient producs available for phosphopeptide enrichment from proteolytic digests or other complex matrices.

GL Sciences' Phos-TiO Kits are the latest addition to our proteomics portfolio.  These kits contain centrifuge spin columns, conditioning and washing buffers, along with waste and collection tubes for both individual column processing and 96-well plate bulk processing.  The titanium dioxide particles contained in the spin columns (available in 1mg/10uL and 3mg/200uL sizes) is specially treated to maximize selectivity for phosphorylated species, and the conditioning and washing buffers contain components to displace the few non-phosphorylated compounds which might originally adhere to the media.  Download data sheet here.

 

Phos-TiO kits require reusable adaptors to secure the spin columns in the waste and collection tubes. (As these adaptors are reusable, they are not components of each kit and much be ordered, once, separately from the kits).  Adaptors are the same for individual 10uL and 200uL tubes, while separate 96-well plate adaptors are available for 10uL and 200uL tips, as shown below:

Phos-TiO kits are extremely selective for phosphopeptides The mass spectra data below shows a comparison of Phos-TiO versus alternative titanium based products as well as IMAC techniques. Phos-TiO shows the best sensitivity, and shows superior enrichment of multi-phosphorylated peptides (4+) compared to IMAC.  In this example, enrichment efficiency of phosphopeptides from a tryptic digest of 2.5 µg β-casein using MALDI-TOF/MS.

Phos-TiO kits are extremely selective for phosphopeptides The following chart shows recovery and selectivity among four commercially available phosphopeptide purification kits in addition to the GL Sciences' Phos-TiO system. Note how Phos-TiO shows virtually zero non-specific adsorption without sacrificing capacity (and, as you will see, recovery).
 

The next chart compares Phos-TiO with IMAC techniques in isolating phosphopeptides from a tryptic digest of 100uG of a HeLa cell lysate. Note the superior selectivity and recovery provided by Phos-TiO technology.

The standardized procedure used with GL Sciences' Phos-TiO Kits consists of four steps with a total processing time typically under 40 minutes. First, the Phos-TiO spin columns are conditioning using the supplied buffer, the sample is then applied, and then rinsed using the supplied rinsing buffer. Purified phosphopeptides are then eluted using an MS-friendly 0.5% ammonium hydroxide solution. Each step of the process is performed using a centrifuge, and Phos-TiO kits require reusable adaptors to secure the spin columns in the waste and collection tubes. (As these adaptors are reusable, they are not components of each kit and much be ordered, once, separately from the kits).  Adaptors are the same for individual 10uL and 200uL tubes, while separate 96-well plate adaptors are available for 10uL and 200uL tips