LIEBERMANN-BURCHARDT 



137 



LIPASE 



Liebermann-Burchardt reaction for choles- 

 terol and its esters {cholesieridcs) . 



1. Modification of A. Schultz. Ex- 

 pose frozen sections of formalin fixed 

 tissue at least 4 days (more in winter) 

 to strong light, if possible sunlight. 

 Mount. Dry carefully with blotting 

 paper. Cover with few drops equal 

 parts acetic and sulphuric acids, l^rain 

 and examine in the reagent. Cholesterol 

 and its esters dark blue or red purple 

 becoming green. 



2. Modification of Romicu (M., C. 

 rend. Acad. d. Sci., 1927, 184, 1206-1208) 

 Mount frozen sections of formol or Bouin 

 (less acetic) fixed tissues and dry. 

 Cover with 1 drop cone, sulphuric acid, 

 3-15 sec. Stop reaction by adding 2-3 

 drops acetic anhydride. Wash with 

 several drops of same. Cover and 

 examine immediately. Cholesterol and 

 its esters violet lilac or red purple, be- 

 coming green. The above two methods 

 abbreviated from Lison (p. 210) are in 

 his excellent judgment specific for 

 cholesterol and its esters if positive. 

 A negative reaction does not definitely 

 prove their absence. See Swyer, G. I. 

 M., Cancer Research, 1942, 2, 372-375 

 for quantitative measurement of the 

 color. 



Light Blue, see Spirit Blue. 



Light Green, see Methyl Green. 



Light Green N, see Malachite Green. 



Light Green SF yellowish (CI, 670) S— acid 

 green, fast acid green N — Commission 

 Certified. This acid di-amino tri- 

 phenyl methane dye is a sulfonated 

 derivative of brilliant green and a 

 valuable counterstain for safranin. It 

 is used by Tv^'ort, F. W., Brit. J. Exp. 

 Path., 1924, 5, 350-351 as a double stain 

 with neutral red for animal parasites 

 and microorganisms in tissues. Un- 

 fortunately light green fades quickly. 

 Conn (p. 110) recommends fast green 

 FCF as a substitute. 



Lighting, see Illumination. 



Lignin Pink, a monazo acid dye (British 

 Drug Houses Ltd.). Advised 0.5% aq. 

 solution as a chitin stain and a contrast 

 stain with chlorazol Black E (Cannan, 

 H. G., J. Roy. Micr. Soc, 1941, 61, 

 88-94). 



Lilienfeld-Monti test for phosphorus is not 

 a satisfactory microchemical method. 

 See Bensley's method (R. R., Biol. 

 Bull., 1906, 10, 49-65) and criticism by 

 Lison (p. 118). 



Lillie's chrom-osmic-acetic fixative. §% 

 aq. chromic acid, 15 cc; 2% aq. osmic 

 acid, 3.5 cc. ; glacial acetic acid, 3 drops. 

 Used by him for echinoderm eggs. 



Line Test for vitamin D. This is the basis 

 for calculating the U.S. P. unit of vita- 

 min D potency. The line test was 



apparently first introduced by McCol- 

 lum, E. v., et al., J. Biol. Chem., 1922, 

 51, 41-49. A critique of the test is 

 given by Bills, C. E., el al., J. Biol. 

 Chem., 1931, 90, 619-636. See also 

 Sherman, H. C., The Chemistry of Food 

 and Nutrition, New York: MacMillan, 

 1941, 611 pp. A slightly modified tech- 

 nique is proposed and given in detail 

 by Martin, G. J., J. Lab. & Clin. Med., 

 1940, 26, 714-719. Inject rats intra- 

 peritoneally with 1 cc. 1% aq. sodium 

 alizarin sulfonate at pH 8.0 and give 

 supplements of measured amounts of 

 vitamin D orally. Animals similarly 

 stained but not given the vitamin serve 

 as controls. After test periods of 1 or 

 2 da3's, kill the animals, remove radii 

 and ulnae and examine grossly and mi- 

 croscopically for alizarin stained lines 

 at epiphysis. See also use of Alizarin 

 Red S. Both this and the sulfonate are 

 better than Madder because they pro- 

 vide quicker and more intense colora- 

 tion of bony calcium laid down during 

 the period that they are available in the 

 circulation as accelerated by vitamin D. 



Linguatulidae, see Parasites. 



Linin (L. linum, flax). The acidophilic, 

 thread-like framework of nucleoplasm 

 seen in sections but not in the living 

 nucleus. 



Lipase. Frozen sections 30;u thick and 4.5 

 mm. in diameter of beef adrenals are 

 extracted in 30% glycerol + equal 

 volume 1% methyl butyrate in glycine 

 — NaOH buffer at pH 8.7; digested at 

 40°C.; enzyme action arrested by addi- 

 tion of 2% phenol (10 parts) and 0.04% 

 brom-thymol blue (1.5 parts) to 3.5 

 times total volume; and end point ti- 

 trated at pH 6.5 with 0.05 N HCl. 

 This point is determined by comparing 

 color with standard color of brom-thy- 

 mol blue in phosphate bulTer pH 6.5. 

 Nearby sections, some stained with 

 hematoxylin and eosin, and others, with 

 Sudan III, are examined histologically. 

 The medulla, which exhibits most 

 lipolj'tic activity, contains least lipid. 

 Estimations of esterase are also de- 

 scribed by Click and Biskind (D.and 

 G. R., J. Biol. Chem., 1935, 110, 575- 

 582). See Barnes, J. M., Brit. J. Exp. 

 Path., 1940, 21, 264-275 for analysis of 

 lipase in lymphocytes and polymor- 

 phonuclear leucocvtes and Hoagland, 

 C. L., et al., J. Exper. Med., 1942, 76, 

 163-173 for lipase determinations in 

 elementary bodies of vaccine virus. 



An important new technique is de- 

 scribed and well illustrated bj^ Gomori, 

 G., Arch. Path., 1946, 41, 121-129: 



1. Fix thin slices of fresh tissue in 

 chilled acetone 12-24 hrs. in ice box. 



2. Dehydrate in 2 changes absolute 



