X-Sulfate K is a slightly off-white to faint-yellowish powder that is used as a chromogenic substrate for aryl-sulfatase. X-Sulfate K yields a blue precipitate when cleaved.

X-α-Gal is a chromogenic substrate for α-galactosidase, yielding a blue precipitate. X-α-Gal is used for detecting two-hybrid interactions directly on the culture media. This substrate eliminates the need for β-galactosidase liquid and filter-lift assays in two-hybrid analysis. Used for species differentiation within the family Enterobacteriaceae and differentiation of Bifidobacteria species from Lactobacilli species.

α-L-Fucosidases are carbohydrate-processing enzymes belonging to the exoglycosidase family of glycoside hydrolases. These enzymes break down glycosidic bonds of sugars at the terminal ends. Fucose –containing glycolipids and glycoproteins can accumulate in different tissues when α-L-Fucosidase is inactive.

X-α-L-fucopyranoside is used as a chromogenic substrate for α-L-Fucosidase, producing a blue precipitate.

XCL1 is a chemokine lacking the first and third conserved cysteine residues usually found in chemokines. It is expressed in thymic and peripheral blood CD8+ T-cells and in natural killer cells. Highest levels of expression are seen in spleen, thymus, small intestine, and peripheral blood leukocytes. XCL1 is chemotactic for natural killer cells and CD4+ and CD8+ T-cells. It assumes two distinct conformations, one of which has been shown to inhibit HIV-1 isolates. XCL1 is a ligand for XCR1 as well as the virus-encoded viroreceptor M3.

GoldBio growth factors are manufactured for RESEARCH USE ONLY and cannot be sold for human consumption!

XTT sodium salt is used in the XTT colormetric assay and assists in identifying metabolic activity within cells. In the XTT assay, the metabolic activity of cells reduces XTT sodium salt to an orange color formazan dye by dehydrogenase enzymes. Dye conversion will only occur in viable cells.

Xylenol Blue is a useful alternative to thymol blue developed in the 1920s. Xylenol Blue can be used at half the concentration that thymol blue requires. It is functional at the same two pH ranges, acidic (pH 1-3), which transitions from red to yellow, and basic (pH 8-10), which transitions from yellow to blue. Xylenol Blue may be substituted for any experiment that requires thymol blue.

Xylitol is a sugar alcohol typically used as a sweetener. In humans it is typically seen to cause remineralization of teeth along with the reduction in cavities. It also is absorbed less than typical sucrose and carries a lower calorie content. Xylitol inhibits the growth of Streptococcus pneumonia and attachment of Haemophilus influenza on nasopharyngeal cells.

Y-β-D-GLC is a chromogenic substrate for β-D-glucosidase, yielding a blue precipitate upon cleavage.

The Yeast Lysis Buffer Kit is useful for extraction of soluble proteins from yeast cells. It is a proprietary improvement on the Zymolyase® based spheroplast preparation and extraction of soluble proteins from yeast cells.

This kit is provided with an optional protocol to make spheroplast and remove lytic enzyme Zymolyase®, prior to lysis and extraction of yeast proteins. Yeast Lysis Buffer is based on organic buffering agents that utilize a mild non-ionic detergent and a proprietary combination of various salts and agents to enhance extraction and stability of proteins. A ready-to-use Zymolyase® preparation is also provided. Depending on application, additional agents such as reducing agents, chelating agents, and protease inhibitors may be added into Yeast Lysis Buffer.

The Yeast Lysis Buffer has been optimized with Saccharomyces cerevisiae and has been tested on several widely used yeast strains. It also works with both gram-positive and gram-negative bacteria. The proprietary combination of this reagent provides a simple and versatile method of yeast protein extraction. Yeast Lysis Buffer eliminates the need for laborious glass bead lysis of yeast cells.

This kit is suitable for processing 100 x 50 µl yeast cell pellet preparations. Yeast Lysis Buffer is also available separately for further downstream processing.

The Yeast Spheroplast Lysis Buffer is useful for extraction of soluble proteins from spheroplast cells. It is a proprietary improvement on the Zymolyase® based spheroplast preparation and extraction of soluble proteins from yeast cells.

Yeast Lysis Buffer is based on organic buffering agents that utilize a mild non-ionic detergent and a proprietary combination of various salts and agents to enhance extraction and stability of proteins. Depending on application, additional agents such as reducing agents, chelating agents, and protease inhibitors may be added into Yeast Lysis Buffer. The Yeast Lysis Buffer has been optimized with Saccharomyces cerevisiae and has been tested on several widely used yeast strains. It also works well with both gram-positive and gram-negative bacteria.

The proprietary combination of this reagent provides a simple and versatile method of yeast protein extraction. Yeast Lysis Buffer eliminates the need for laborious glass bead lysis of yeast cells.

Yeast Extract Mannitol (YEM) media is often used for the growth of Agrobacterium as well as Rhizobium bacterial strains. Mannitol is used as a sugar substitute to provide a carbon source while the yeast extract provides the nitrogen for bacterial growth.

YEM media is a complex media formulation that provides optimal and stress free growing conditions for cultures of both Agrobacterium and Rhizobia.