The primary use of this antibody conjugate is for the detection of SPHK1 in intact cells by direct immunolabeling methods such as flow cytometry or immunofluorescence microscopy. SPHK1 is one of the enzymes involved in sphingolipid metabolism. SPHK1 catalyzes the phosphorylation of sphingosine to sphingosine-1-phosphate. This reaction plays an important role in determining cell proliferation versus cell death.{13916,14481} SPHK1 is found in a wide variety of tissues and cell types including kidney, liver, spleen, heart, platelets, and human tumors.{13076} On a cellular level, it is found in the cytosolic and membrane fractions.{14482} Based on the amino acid sequence, this protein has a molecular weight of approximately 43 kDa. Some reported post translational modifications may explain the shift in band migration to 50 kDa.{14483} NOTE: Multiple isoforms of SPHK1 are known and one is 470 amino acids. This likely explains the 50 kDa band observed.