Color and transparency are determined from visual observation of the sample. Normal urine is straw yellow to amber in color. Abnormal colors include bright yellow, brown, black (gray), red, and green. These pigments may result from medications, dietary sources, or diseases.
limulus amebocyte lysate test. limulus amebocyte lysate test. LAL test. A test used to detect minute quantities of bacterial endotoxins and to test for pyrogens in various materials; it is also used to detect septicemia due to gram-negative bacteria. Limulus amebocyte lysate is formed from the lysed circulating amebocytes of the horseshoe crab (Limulus polyphemus).
Water-siphon test. Dr Henry Knipe â and Dr Marcin Czarniecki â et al. The water siphon test may be performed as part of a barium swallow to assess for gastro-oesophageal reflux in a hiatal hernia. It is performed in the supine RPO position with the patient drinking water continuously. The test is said to be positive if there is visible barium reflux in the oesophagus.