Filtration Sample Preparation (17)
Filtration Sample Preparation"Orochem’s vast selection of filtration plates allow preliminary mode of sample preparation of complex matrices. Often pre-filtration of plasma, serum and other biological fluids may be sufficient for sample preparation for chromatographic methods. Recommended for Dilute and Shoot and for sample clean up prior to HPLC and Micro arraying.
Low Protein Binding
OverviewOrochem's low protein binding filters are ideal for removing particles from HPLC samples, tissue culture media filtration, and general biological sample filtration.
- Different types of filters:
- Regenerated cellulose: hydrophilic, solvent resistant, pH range 3-12. Low and no-specific adsorption.
- Hydrophilic PVDF: solvent resistant, low protein binding, low levels of UV adsorbing extractable.
- Different formats: columns and 96-well plate
High Protein Binding
OverviewOrochem offers hydrophobic PVDF filter columns with 0.2 and 0.45 micron frit. They have high chemical compatibility, and high levels of protein binding.
FeaturesDifferent formats: cartridge, also can pack into 96-wellplate, please contact us for detail information.
MatriKleen Extraction (1)
MatriKleen Extraction PlateMatriKleen Extraction Plate is a new generation sample preparation device which effectively removes most unwanted interferences from biological samples and eliminates ion suppression for mass spectrometry analysis.
- In both 3 cc cartridge and 2 cc/well 96-well plate format, larger cartridge format is also available
- Designed for plasma, serum, and blood samples
- Universal extraction tool for:
- Polar and non-polar chemicals
- Acidic and basic analytes
- Quick and simple high throughput procedure
- Total process time
- Eliminates matrix effect from phospholipids and proteins
- High recovery and reproducibility for most drug compounds
- Place MatriKleen extraction plate and collection plate on top of positive pressure processor (or vacuum manifold).
- Add 400 μL of methanol-acetonitrile mixture (1/1, v/v) to MatriKleen plate first, followed by 100 μL sample (spiked with target analyte).
- Wait about 5 minutes. Apply positive pressure or vacuum, adjust pressure so the sample flows through drop by drop.
- When all of solution is out, increase pressure to dry the plate for about 30 seconds.
- The eluate in the collection plate is ready to be analyzed.
Phospholipid Depletion (3)
Phospholipid DepletionPurity is a unique phospholipid depletion device which integrates filtration with targeted removal of phospholipids and proteins in plasma/serum. The phospholipid retention mechanism is based on highly selective Lewis acid-base interaction between the ions (functionally bonded to the sorbent) and the phosphate moiety consistent with all phospholipids.Features
- Both in column and 96-well plate formats
- Two different types of filters available, 0.45 and 0.20 micron.
Protein Crash Plate and Protein Precipitation Plate (10)
Protein Crash Plate and Protein PrecipitationProtein precipitation is a common protocol for rapid sample clean-up and extraction of pharmaceuticals from blood samples (whole blood, plasma and serum) during drug discovery. It also allows the disruption of drug binding to proteins. Blood samples from various species such as dogs, rats, mice, and humans show variations in their compositions, but often only a single bioanalytical method covers all these species. Protein precipitation denatures the protein and destroys its drug binding ability, depending on the binding mechanism.An organic solvent, acid, salt, and metal have been used for effecting protein precipitation by exerting specific interactive effects on the protein structure. An organic solvent lowers the dielectric constant of the blood protein solution and also displaces the ordered water molecules around the hydrophobic regions on the protein surface, the former enhancing electrostatic attractions among charged protein molecules and the latter minimizing hydrophobic interactions among the proteins. Thus, the proteins aggregate and precipitate. Acidic reagents form insoluble salts with the positively charged amino groups of the proteins at pH values below their isoelectric points (pIs). High salt concentrations deplete water molecules from the hydrophobic protein surfaces and allows aggregation through hydrophobic interactions of protein molecules. Binding of metal ions reduces protein solubility by changing its pI. Variation in ionization effects for different species of plasma using acetonitrile in 50:50 methanol:water is also a good choice. Here is the summary of some study results:
- The most efficient precipitants for protein removal were zinc sulfate, acetonitrile, and trichloroacetic acid (at 2:1 volume of precipitant to plasma, the protein removal values were, respectively, 96, 92, and 91% with <1% RSD for n = 5).
- The chosen precipitants functioned universally for all plasmas.
- Using acidic components exerted significant effects on ionization efficiency.
- Pure mobile phases with organic precipitants produced the largest ionization effects.
- Available both cartridge and 96-well plate formats. Both can be used with positive pressure processor, vacuum manifold, or centrifuge.
- Protein crash kit has one protein crash plate, one collection plate and one cap mat.
- No solvent leakage during mixing, incubation and zero crosstalk.
OroQ QuEChERS Dispersive Products
- Remove water, organic acids, sugars, fatty acids and pigments from sample
- Design for AOAC and other QuEChERS methods
- Application in pesticide and food ingredients analysis
- Fit for GC, HPLC, and Ambient Mass spectrometry analysis
- Pack directly in centrifuge tubes for convenience
- Available in customized forms or contents
Sample Preparation Perspectives (1)
Sample Preparation Perspectives
OverviewThe sample preparation step in an analytical process typically consists of an extraction procedure that results in the isolation and enrichment of components of interest from a sample matrix. Extraction can vary in degree of selectivity, speed, and convenience and depends not only on the approach and conditions used but on the geometric configurations of the extraction phase. Increased interest in sample preparation research has been generated by the introduction of nontraditional extraction technologies. These technologies address the need for reduction of solvent use, automation, and miniaturization and ultimately lead to on-site in situ and in vivo implementation. These extraction approaches are frequently easier to operate but provide optimization challenges. More fundamental knowledge is required by an analytical chemist not only about equilibrium conditions but, more importantly, about the kinetics of mass transfer in the extraction systems. Optimization of this extraction process enhances overall analysis. Proper design of the extraction devices and procedures facilitates convenient on-site implementation, integration with sampling, and separation/quantification, automation, or both. The key to rational choice, optimization, and design is an understanding of the fundamental principles governing mass transfer of analytes in multiphase systems. The objective of this perspective is to summarize the fundamental aspects of sample preparation and anticipate future developments and research needs.
1. Why Sample Preparation is needed?Sample preparation has, for a long time, been a relatively neglected part of the systems for chemical analysis. Often, sample preparation has been performed by highly manipulative multi-step procedures using methods such as conventional liquid-liquid extraction. As other parts of the analytical procedures, e.g. separation and detection, have been further developed, sample preparation has, in many cases, become somewhat of a bottleneck in the total procedures. Because of this, sample preparation has attracted increasing attention during recent years, and the need for new improved methods has been largely recognized. Indeed, there has been a major change in the general attitude towards sample preparation. Frequently, it was earlier considered as a separate procedure prior to the real analysis while it nowadays has become a, more or less, integrated part of the analytical procedure. To be able to develop sample preparation methods to new much more advanced levels that are, or will be, required, it is necessary to base their development on a systematic and scientific approach. Thus fundamental understanding of the different processes involved in a sample preparation method should serve as a basis for its optimization. This is in contradiction with the earlier oftentimes applied practical approach. In the opinion of the author, a key to the recent development is, in the first place, miniaturization, thus adapting to the general trend in analytical chemistry. Indeed, this is a presupposition for the integration of sample preparation in the total analysis systems. Such matching of the different parts of the analysis system has led, and will lead, to improved over-all performance. This concerns qualities such as accuracy and precision, sensitivity, selectivity, throughput and cost-effectiveness. The current interest in new sample preparation methods has resulted in the recent publication of a number of books and reviews on this topic. In many application areas, there is an urgent need for faster analyses—high-throughput analyses. In the pharmaceutical industry, approaches such as combinatorial chemistry and parallel synthesis provide a means of production of large numbers of compounds to be used for drug-discovery experiments. For determination of the physiological performance of a drug it has to be determined in various biological fluids. This inevitably leads to an increase in the number of biological samples for pharmacokinetic analysis. At the same time, desired concentration levels for quantitative analysis have been reduced. All this puts bioanalytical chemistry under pressure to provide methods for high-throughput analysis at low analyte concentration levels. This situation has been described in a number of reviews. It seems that the need for high throughput can be met by application of automated integrated analytical systems which include the sample clean-up. As increased throughput is achieved for sample preparation, the bottleneck will move to another part of the analysis chain! The major goal of sample preparation is to prepare the sample for the separation/ detection part of the analysis. For drug analysis in plasma or whole-blood samples, the sample preparation should thus remove the drug from the matrix for quantification, separate the drug from endogenous interfering components, and, if needed, concentrate the drug. To anyone practicing analytical chemistry, a sample preparation method should fulfil the following requirements: it should be easy to handle, be fast and robust, automated, and operated at a low cost/sample. The recovery, accuracy, and precision should be within internationally accepted limits. Further, high throughput should be provided. These goals cannot be met by traditional methods and that is why these are currently being further developed. - Source: Bloomberg, Anal. Bioanal. Chem. 2009, 393, 797-807
2. Sample preparation geared to LC-MSThe sample preparation method must be adapted to the demands of the separation/ detection part that follows. Current methods for quantitative bioanalysis, in general, include LC coupled to tandem mass spectrometry, LC-MS-MS. Often, multiple reaction monitoring (MRM) is used. Due to the high selectivity of the MRM, it might be considered unnecessary to separate the analytes in the LC column. This would facilitate the use of generic LC methods, which are often called for. Thus it would usually not be necessary to develop LC methods tailored to different types of sample. However, the analysis is complicated by the possible presence of ion suppression, sometimes called matrix ionization, at the LC-MS interface. Interferences co-eluting with the analyte from the LC-column may thus compete in the analyte ionization process leading to reduced or enhanced analyte signal. For plasma samples, the ion suppression may, depending on the matrix, differ from sample to sample and quantitative analysis thereby becomes compromised. The degree of ion suppression depends on type of ionization technique used, where ESI is usually more sensitive to this effect than APCI. Further, the type of interface matters, where Z-spray < orthogonal spray linear spray geometries. The risk of ion suppression puts high demands on the sample preparation. In fact, the risk of ion suppression is a factor that sets the currently necessary level of sample preparation for LC-MS-MS. Interferences remaining after the sample preparation may be removed from the analytes in the LC separation step. Interferences are likely to be eluted in the LC front where unretained compounds are eluted or at the end of the elution gradient, where strongly retained compounds are eluted; therefore it is desirable to have the analytes well away from the front and the end of the gradient. To achieve this, the gradient may have to be adjusted in some cases. A certain degree of separation in the LC is thus desirable, which may come into conflict with the wish for very short LC-run times.
About matrix components and endogenous materials in human plasma:Biological matrices include plasma, serum, cerebrospinal fluid, bile, urine, tissue homogenates, saliva, seminal fluid, and frequently whole blood. Quantitative analysis of drugs and metabolites containing abundant amounts of proteins and large numbers of endogenous compounds within these matrices is very complicated. Direct injection of a drug sample in a biological matrix into a chromatographic column would result in the precipitation or absorption of proteins on the column packing material, resulting in an immediate loss of column performance (changes in retention times, loss of efficiency and capacity). Similar damage can occur to different components of the ESIMS/MS system commonly utilized for analyzing drugs. Matrix components identified by different analytical techniques are shown in the Table below. Major classes encountered in plasma consist of inorganic ions/salts, proteins and/or macromolecules, small organic molecules, and endogenous materials.
3. Sample preparation for herbal medicines/supplementsPlants are naturally gifted at the synthesis of medicinal compounds. The extraction and characterization of active compounds from medicinal plants have resulted in the discovery of new drugs with high therapeutic value. A classic example is aspirin, which was initially discovered as salicylic acid in willow bark and leaves; another noted example is taxol, recently proven to be effective against breast and ovarian cancers, which was initially discovered in bark of yew trees. The use of medicinal plants (herbs) has a long history throughout the world and herbal preparations, including herbal extracts, can be found in the pharmacopoeias of numerous countries. In recent years there have been a renaissance of interest in natural or herbal remedies worldwide, partly because of the realization that modern medicine is not capable of providing a “cure-all” solution against human diseases and that the presence of unwanted side-effects is almost unavoidable. Unlike modern drugs that invariably comprise a single active species, herb extracts and/or prescriptions contain multiple active constituents. Interestingly, natural compounds contained in these “herbal cocktails” can act in a synergistic manner within the human body, and can provide unique therapeutic properties with minimal or no undesirable side-effects. A key factor in the widespread acceptance of natural or alternative therapies by the international community involves the “modernization” of herbal medicine. In other words, the standardization and quality control of herbal materials by use of modern science and technology is critical. At present, however, quality-related problems (lack of consistency, safety, and efficacy) seem to be overshadowing the potential genuine health benefits of various herbal products, and a major cause of these problems seems to be related to the lack of simple and reliable analytical techniques and methodologies for the chemical analysis of herbal materials. Sample preparation is the crucial first step in the analysis of herbs, because it is necessary to extract the desired chemical components from the herbal materials for further separation and characterization. Thus, the development of “modern” sample preparation techniques with significant advantages over conventional methods (e.g. reduction in organic solvent consumption and in sample degradation, elimination of additional sample clean-up and concentration steps before chromatographic analysis, improvement in extraction efficiency, selectivity, and/or kinetics, ease of automation, etc.) for the extraction and analysis of medicinal plants is likely to play an important role in the overall effort of ensuring and providing high quality herbal products to consumers worldwide. - Source: Carmen W. Huie, Anal. Bioanal. Chem. 2002, 373, 23-30
4. Sample preparation for food samples and complexity of food matricesThe term “food” refers to the broad range of edible materials that comprise the essential body nutrients required for life and growth, such as proteins, carbohydrates, fats, vitamins, or minerals. Foodstuffs are described variously as “liquid” or “solid”, and “wet” or “dry”, depending on the amounts of water and fat they contain. Samples of plant origin are classified for analytical purposes as having a high or medium water content and a lower content of saccharides (from 5% to 15%), very low water content (dry), or a high content of oils. Similarly, food samples can be divided into four main groups based on water and fat content. Food samples of biological origin (liquid or solid) have been divided generally into the five categories: milk, eggs, other samples of animal origin (e.g. muscle, liver, and fat), plant material, food (meat, fish, cereals, wine, juice, oils, sugar, etc). This coarse division is important when considering the choice of isolation technique, extraction solvent, and sample clean-up method during an analytical procedure.
5. Sample preparation in CosmeticsRecent concerns about UVA and UVB radiation from the sun contributing to skin cancers have highlighted the importance of applying an effective sunscreen before exposure to these harmful rays. As sunscreens are categorized as drug products by the U.S. Food and Drug Administration (FDA), they must undergo rigorous testing before being released to market. Proposed changes to the FDA regulations governing the labeling of sunscreen products are also expected to come into force by the end of 2009, which will require manufacturers to supply information to regulators on the UVA screening provided by its products. As a result of regulatory concerns, an efficient means of analysis is needed that can provide fast and dependable measurements of UV-absorbing compounds. There are many available techniques for analyzing these compounds, including thin layer chromatography (TLC), gas chromatography (GC) and high performance liquid chromatography (HPLC). However, the oily matrix of sunscreen lotions coupled with the high UV absorbance of the analytes makes ultra high performance liquid chromatography (UHPLC) the method of choice for analyzing sunscreens. By additionally using photodiode array detection, the complete absorption spectrum of each compound is obtained as it elutes. The sensitivity of HPLC/PDA is also sufficient to measure these compounds in environmental water samples, which facilitates research on exposure and environmental fate.
SAMPLE PREPARATION PROTOCOLS IN USEA number of advances have been made during the past decade to convert sample preparation techniques used for about 30 years for the clean-up of drugs in biological matrices into formats that are amenable for high volume processing with or without automation. Detailed accounts about the fundamentals of these techniques can be found in several books, reviews and articles published in the literature. Therefore, only brief descriptions of the principles of these methods will be summarized. For isolating drugs and metabolites from biological and other complex matrices, several approaches have been reported, which consist of:
- Solid phase extraction (SPE)
- Liquid-liquid extraction (LLE)
- Protein precipitation (PPT)
- Affinity separations (MIP)
- Membrane separations
- Preparative high performance liquid chromatography (HPLC)
- Solid phase micro extraction (SPME)
- Ultrafiltration and micro dialysis
- Concentrate analyte(s) to improve limits of detection and/or quantitation
- Exchange analyte from a non-compatible environment into one that is compatible with chromatography and mass spectrometric and/or other instrumental analytical techniques
- Remove unwanted matrix components that may interfere with the analysis of the desired compound
- Perform selective separation of individual components from complex mixtures, if desired
- Detect toxins in human system or in environment (air, drinking water, soil)
- Identify stereochemical effects in drug activity and/or potency
- Follow drug binding to proteins
- Determine stability and/or absorption of drugs and follow their metabolism in human body
How to select the most appropriate Sample Preparation MethodShould depend on three specific criteria:
- Requirements of the assay
- Time allowed to run sample prep method
- Possible investment towards method development time
- Requires rapid sample turn around
- Higher limits of quantitation
- Very little method development time (1-2 days)
- Protein Precipitation may be ideal choice
- Drugs more potent and dosed at lower levels
- Requires ultra-sensitivity, great selectivity and rugged method development
- Greater method development time (3-5 days)
- SPE is the more ideal choice
Solid Phase Extraction (494)
Solid Phase Extraction"SPE is a method of sample preparation that concentrates and purifies analytes from solution by sorption onto a sorbent contained in either a disposable solid phase cartridge or a 96-well plate, followed by elution of the analyte with a solvent and reconstitution into a mobile phase that is appropriate for the instrumental method used for analysis” (E.M.Thurman and M.S.Mills, Solid-Phase Extraction – Principles and Practice, John Wiley, New York, 1998)
General Steps of an SPE protocol:
- Sample Pre-treatment: Dependent on compound of interest, sample matrix, and nature of retention chemistry; involves pH adjustment, centrifugation, filtration, dilution, buffer addition, etc.
- Conditioning: Solvent is passed through the SPE material to wet the bonded functional groups => ensures consistent interaction.
- Equilibration: Sorbent/ phase is treated with a solution that is similar (in polarity, pH, etc.) to the sample matrix => maximizes retention.
- Sample Load: Introduction of the sample = analytes of interest are bound/ extracted onto the phase/sorbent.
- Washing: Selectively remove unwanted interferences co-extracted with the analyte without prematurely eluting analytes of interest.
- Elution: Removing analytes of interest with a solvent that overcomes the primary and secondary retention interactions between sorbent and analytes of interest.
- Evaporation of eluent/ reconstitution with mobile phase (optional).
Strategies in carrying out SPEThere are 3 different elution strategies in SPE. Which one to choose depends on the goal of the extraction.
i. Bind-Elute Strategy
- Most common
- Bind: Analytes bind to tube, unwanted matrix components are washed off
- Elute: Eluant changed to remove analytes from tube
- Analytes are concentrated via evaporation prior to HPLC or GC analysis
ii. Interference Removal Strategy
- Bind all unwanted matrix components and allow analytes to pass through during the sample loading stage
- Like chemical filtration
iii. Fractionation Strategy
- Retain and sequentially elute different classes of compounds by modifying eluant pH or % organic
SPE Products Selection Guide
Stationary Phase Selection Guide
SPE Hardware Selection Guide
Oro-Sep SPE CartridgesOro-Sep Cartridges are molded from medical grade virgin polypropylene, fritted with 20 micron PE frits and are compatible with a syringe or a vacuum manifold. The female luer tip inlet of the cartridge allows connection to a syringe tip. The male luer tip outlet connects to a vacuum manifold. Sep-Pak®cartridges may be substituted with Oro-Sep cartridges. Oro-Sep cartridges packed with reversed phases, normal phases, and ion exchange phases in three different bed sizes, may be utilized for sample preparation and sample concentration in the bio-tech, clinical, environmental, forensic, and pharmaceutical arena.
SuPErscreen Disc - SPEOrochem Technologies has now developed SuPErScreen, a proprietary high capacity silica particle embedded glass fiber for Disc Solid Phase Extraction. Elimination of sorbent fines and decreased sample elution columns provide cleaner extracts which allows you to bypass evaporation prior to detection. SuPErScreen Silica impregnated glass fiber discs are manufactured using both long and short glass fibers offering greater porosity of the matrix. With silica particles present as an integral component during manufacturing, uniform distribution of silica is achieved across the thickness of the disc membrane. A typical 8 mm diameter OROCHEM disc in a 3 ml column contains approximately 13.8 mg of silica.
OmniSorb SPE Plates
- Omnisorb 96 well filter plates are ideal for all SPE applications and High Throughput Screening.
- 1ml sample volume per well Robotic and liquid handling compatibility Choice of chemistries.
- Made from solvent resistant, low extractable polypropylene with unique drip directors.
Orochem 2000 Sorbent filled SPE Plate
Features & BenefitsOROCHEM 2000 SPE 96-well Plates are packed with Orpheus silica based sorbents that have broad selectivity and resist occlusion by proteinaceous materials from samples. Non-occlusion of sorbents, combination of size exclusion and adsorption chromatography allows efficient flow characteristics, enhanced detection, and cleaner extracts. The 2.2 mL/well SPE plates manufactured from virgin medical grade polypropylene have the SBS standard footprint. Individually fritted wells eliminate cross-talk; the larger exit diameter of the well enables a faster flow rate. The OROCHEM 2000 Vacuum Manifold is designed to accommodate every filter plate, and comes with inserts to accommodate collection plates of all sizes, including shallow well plates
ApplicationsSample preparation by Solid Phase Extraction in drug development, drug analysis, pharmacokinetics, and biotechnological applications.
Orochem SuPErscreen Disc- SPE Plate
Features & BenefitsOrochem SuPErScreen Disc SPE is manufactured using both long and short glass fibers offering greater porosity of the matrix. With silica particles present as an integral component during manufacturing, uniform distribution of silica is achieved across the thickness of the disc membrane. The use of thick glass fibers offers increased contact with the phase. With SuPErScreen disc SPE, an 8mm diameter disc allows 13.8 mg and a 6mm disc in a 96-well format allows 7.6mg /well media loading capacity.
ApplicationsSample preparation by Solid Phase Extraction in drug development, drug analysis, pharmacokinetics, and biotechnological applications.
Orochem 3000 384-well Disc SPE PlateOrochem 3000 SPE plates are available with SuPErScreen glass fiber based SPE discs. The high throughput 384-well SPE plate enables a four-fold higher sample preparation capability. Orochem 384-well SPE plates offer yet another example of our capabilities to customize sample preparation.
Special Plate for Synthesis Macromolecule (22)
Synthesis MacromoleculesFor high throughput screening (HTS) applications (e.g. purification of combinatorial libraries or screening pharmaceuticals in biological fluids).It is available in the versatile 96-well format. In this format, 20 um of frit is packed into your choice of 1 ml or 2ml Array column. These are suitable for extraction of 150 – 200 uL of aqueous sample. The columns can be used individually, or assembled into the plate format. Pre-assembled plates can also be purchased. The plate can be populated with as many or as few columns as required, making this a flexible, economical format.
Supported Liquid-Liquid Extraction (5)
Supported Liquid-Liquid ExtractionTraditional LLE utilizes large volumes of solvents that are often hazardous from an environmental perspective and the process is tedious and time consuming. During the past decade, this technique has undergone a spectacular transformation in the context of high-throughput screening with the introduction of miniaturized protocols along with revolutionary membrane-based and solid support based technologies. These advances were reviewed by several authors. The simplest technique is the use of the 96-well collection plate format (analogous to the format used in SPE) in conjunction with a liquid handling robotic system; it follows the same principle as bulk scale LLE.However, immobilization of the aqueous plasma sample on an inert solid support medium packed in a cartridge or in the individual wells of a 96-well plate and percolating a water immiscible organic solvent to extract the analyte from this medium evoked significant enthusiasm from the pharmaceutical industry. Orochem Aquamatrix cartridges and plates are packed with flux calcined diatomaceous earth for high capacity retention of analytes. Also Available with Diatomaceous Earth at buffered pH of 4.5 and 9.0.
Features and Applications
- Packed with chemically inert material, stable in the pH range 1-13.
- Plates compatible with robotic liquid handlers for automated extraction.
- Allows high through put alternative to traditional liquid-liquid extraction techniques.
- Eliminates steps like mixing, centrifugation and organic phase separation.
- Provides support, greater surface area and accelerated solvent extraction.
- No pre-treatment of the bed is necessary.
Vitamin D Metabolites Extraction Plate (1)
Vitamin D metabolites extraction plateOrochem newly patented Vitamin D Metabolites Extraction plate is specifically designed for vitamin D metabolites analysis in clinical laboratory. The Vitamin D Metabolites extract plate provides for the extraction from human plasma or serum samples comprising vitamin D metabolites such as 1,25-dihydroxy vitamin D3 and D2, 25-hydroxy vitamin D2, and D3 from protein binding, removal of protein and phospholipids, and isolation of the metabolites using a combination of ion-exchange and Lewis acid mechanisms without the requirement to acidify the samples. The recommended method and the plate provides higher recoveries of vitamin D metabolites than existing phospholipid depletion plate techniques. Accurate quantification of 1,25-dihydroxy vitamin D and 25-hydroxy vitamin D metabolites is useful in differential diagnosis of vitamin D-related diseases and for monitoring vitamin D therapy in patients with chronic renal disease.Features
- In 2 cc/well 96-well plate formate. Cartridge format is also available
- Recommended protocol
- 96-well format, 4 steps, totally less than 20 minutes per plate
- Simple, minimum training required
- Consistent and high recovery
- No matrix effect