title: An improved technique for collection of human tears.
abstract: While pursuing a study of lysozyme levels in human tears, the authors were dissatisfied with collection systems previously used. We therefore constructed a new, improved apparatus for tear collection using a thin, flexible polyethylene tube attached to a standard 25-gauge 1.0 cc tuberculin syringe. This system is superior to previously-designed apparati in that it permits the collection of a relatively large volume of tears in a short time without risking damage to delicate ocular structures. This promises to enhance the reliability of tear chemistry research without significantly adulterating the chemical composition of the samples. Typical results for total protein, levels of IgA and lysozyme, and Minimum-Inhibitory-Concentration bioassay of tears are presented to support the authors' position that standard chemical assays are not altered. An additional bonus inherent in this technique is the potential for obtaining larger populations of experimental subjects due to the low level of irritation that subjects experience when tears are sampled. This apparatus is easily amenable to clinical and medical diagnostic studies of tear chemistry in patients suffering from various eye diseases.
mesh_terms: D001681:Biological Assay; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism; D007765:Lacrimal Apparatus / Q000378:metabolism*; D009113:Muramidase / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D013048:Specimen Handling / Q000295:instrumentation*; D013666:Tears / Q000201:enzymology / Q000378:metabolism*
chemical_list: D007070:Immunoglobulin A; D011506:Proteins; D009113:Muramidase