Abstract: The present invention started when a .lambda.gt11 cDNA library of normal human melanocytes was screened with antibodies directed against purified hamster tyrosinase. Two important cDNA clones were isolated: cDNA .lambda.mel 34 and .lambda.mel 17-1. It is concluded that .lambda.mel 34 contained cDNA encoding human tyrosinase. Moreover, the cDNA gene for human tyrosinase was recovered from the .lambda.mel 34 and can be used for many purposes including the production of pure human tyrosinase. This gene and its promoter are characterized herein. Studies suggested that .lambda.mel 17-1 gene product act on melanin biosynthesis's pathway distal to tyrosinase. Melanocytes preferentially express an mRNA species, Pmel 17, whose protein product cross reacted with anti-tyrosinase antibodies and whose expression correlated with the melanin content. The deduced protein structure has been analyzed and its chromosomal location in mouse and man has been mapped.

Abstract: The discovery of this invention is that the use of an aseptic barrier in the form of a layer of material which is impervious to the passage of water in combination with at least one layer of absorbent tissue in the form of a disposable tissue or handkerchief can function to reduce materially the transfer of pathogens such as viruses and bacteria from the bodily internal products, mucous and fluid effluent from inside a person to his hand. The above principles may be embodied in a disposable tissue including an aseptic barrier or in a method of entrapping nasal secretions in such a way that contamination of the environment from infected noses be avoided. This is accomplished by the creation of a trap in the form of a mitten-like bag, resistant to the passage of aqueous liquids, with facial tissue affixed to the outside of this mitten-like bag.

Abstract: This discovery resulted when a .lambda. gt11 cDNA library of normal human melanocytes were screened with antibodies directed against purified hamster tyrosinase. Sixteen independent clones which gave a positive signal were isolated from 5.times.10.sup.5 independent plaques. cDNA inserts of 13 clones among the 16 candidates cross-hybridized with each other, indicating that they were from related mRNA species. mRNA homologous to a representative cDNA .lambda. mel 34 was expressed specifically in melanocytes, detecting an approximately 2.4 kb mRNA species of human melanocytes. The nucleotide sequence of the three overlapping cDNA inserts spanning 1.88 kb was determined and an amino acid sequence was deducted. The human tyrosinase is composed of 548 amino acids with a molecular weight of 62,160 excluding a hydrophobic signal peptide. Mouse genomic DNA blot analysis revealed that the gene for .lambda. mel 34 was deleted in albino mouse homozygous for the deletion at and around the albino locus on chromosome 7.