Taurochenodeoxycholic acid-d4 (TCDCA-d4) is intended for use as an internal standard for the quantification of TCDCA (Item No. 20275) by GC- or LC-MS. TCDCA is a taurine-conjugated form of the primary bile acid chenodeoxycholic acid (CDCA; Item No. 10011286).{33901} Serum levels of TCDCA increase approximately 5-fold within two hours and begin to decrease within four hours during an oral lipid tolerance test in humans.{33902} Serum levels of TCDCA are increased in patients with liver cirrhosis and may serve as a marker of disease progression.{33903} TCDCA-d4 MaxSpec® standard is a quantitative grade standard of TCDCA-d4 (Item No. 21905) that has been prepared specifically for mass spectrometry and related applications where quantitative reproducibility is required. The solution has been prepared gravimetrically and is supplied in a deactivated glass ampule sealed under argon. The concentration was verified by comparison to an independently prepared calibration standard. This TCDCA-d4 MaxSpec® standard is guaranteed to meet identity, purity, stability, and concentration specifications and is provided with a batch-specific certificate of analysis. Ongoing stability testing is performed to ensure the concentration remains accurate throughout the shelf life of the product. Note: The amount of solution added to the vial is in excess of the listed amount. Therefore, it is necessary to accurately measure volumes for preparation of calibration standards. Follow recommended storage and handling conditions to maintain product quality.
Available on backorder
A quantitative analytical standard guaranteed to meet MaxSpec® identity, purity, stability, and concentration specifications
Formal name: 2-[[(3α,5β,7α)-3,7-dihydroxy-24-oxocholan-24-yl-2,2,4,4-d4]amino]-ethanesulfonic acid
Synonyms: Taurochenodeoxycholate-d4|TCDCA-d4
Molecular weight: 503.7
CAS: 1207294-24-3
Purity: ≥95%
Formulation: A solution in methanol at 100 µg/ml
The maintenance of embryonic stem cells in culture typically requires feeder cells and various exogenous factors found in serum. Murine embryonic stem (mES) cells can be maintained in the absence of feeder cells and serum but require the leukemia inhibitor factor (LIF) and bone morphogenic protein (BMP) to prevent differentiation and promote self-renewal. SC-1 is a small molecule activator of stem cell renewal that allows the propagation of OG2 mES cells for at least 10 passages in an undifferentiated state.{14533} The activity of SC-1 is mediated by the combined inhibition of RasGAP and ERK1 with Kd values of 98 and 212 nM, respectively.{14533} Inhibition of RasGAP increases Ras signaling via the PI3-kinase pathway which promotes self-renewal, whereas inhibition of ERK blocks differentiation.
Available on backorder
The tetracycline repressor (TetR) is a transcriptional regulator which normally binds tightly to its palindromic tetO operator DNA, blocking gene expression.{17508} Tet causes the repressor to dissociate from the DNA, allowing transcription to occur. A novel reverse TetR (revTetR) requires tetracycline as a co-repressor to bind tetO and block transcription.{17509,17510} Anhydrotetracycline (hydrochloride) is a powerful effector in both the tetracycline repressor (TetR) and reverse TetR (revTetR) systems, binding the Tet repressor 35-fold more strongly than Tet.{17508,17511} Moreover, anhydrotetracycline poorly binds the 30S ribosomal subunit, compared to Tet,{17512} so it does not act as a general inhibitor of translation and is a poor antibiotic. Perhaps related to this, the concentration of anhydrotetracycline that inhibits eukaryotic cell growth is more than a 1,000-fold above the dose that alters transcription through TetR.{17508}
Available on backorder
The PtdIn phosphates play an important role in the generation and transduction of intracellular signals.{8344,4096,14518} PtdIns-(3,4,5)-P3-biotin is an affinity probe which allows the PIP3 to be detected through an interaction with the biotin ligand. This design allows PtdIns-(3,4,5)-P3-biotin to serve as a general probe for any protein with a high affinity binding interaction with inositol-(3,4,5)-triphosphate phospholipids, such as phosphatidylinositol 3-kinase, PTEN, or PH-domain-containing proteins.
Available on backorder
The PtdIn phosphates play an important role in the generation and transduction of intracellular signals.{8344,4096,14518} PtdIns-(3,4,5)-P3-biotin is an affinity probe which allows the PIP3 to be detected through an interaction with the biotin ligand. This design allows PtdIns-(3,4,5)-P3-biotin to serve as a general probe for any protein with a high affinity binding interaction with inositol-(3,4,5)-triphosphate phospholipids, such as phosphatidylinositol 3-kinase, PTEN, or PH-domain-containing proteins.
Available on backorder