SPECIFIC GRAVITY 



321 



SPORE STAIN 



without the negative pressure. This 

 method can be used for many tissues 

 besides embryos. For author's account 

 see Spalteholz, W., Ueber das Durch- 

 sichkigmachen von menschlichen und 

 Tierischen Praparaten. Leipzig, 2nd 

 Edition, 1914. 



Specific Gravity. It is often desirable to 

 ascertain the relative specific gravities 

 of tissues, cells and parts of cells. See 

 Centrifugation. 



Spectrographic Analysis, see Histospectrog- 

 raphy and Absorption Spectra. 



Spectrophotometric Analysis of tissue stain- 

 ing has been greatly advanced by 

 Stowell, R. E. and Albers, V. M., Stain 

 Techn., 1943, 18, 57-71. Comparison 

 of spectral absorption curves of stains 

 and substances colored bj^ them has 

 demonstrated that data can thereby be 

 obtained on the chemical processes in- 

 volved. No evidence was found of sig- 

 nificant chemical alterations in the 

 chromophox radicals of the stains asso- 

 ciated with the tissue staining under the 

 conditions of the experiments. 



Spectrophotometric Evaluation of blood 

 stains (Lillie, R. D. and Roe, M. A., 

 Stain Techn., 1942, 17, 57-63). 



Spermatozoa, simple method for staining. 

 Make smears of fresh spermatic fluid on 

 slides and dry in air. Fix 3 minutes in 

 10% formalin. Stain in Harris' hema- 

 toxylin 1 minute, wash in water and dry 

 (Fetterman, G. H., Am. J. Clin. Path., 

 1942, 6, 9). Microincineration (Poli- 

 card, A., Bull. d'Hist. Appl., 1933, 10, 

 313-320). Helpful histochemical meth- 

 ods are detailed by Marza, V. B., 

 Bull, d'hist. appl., 1931, 8, 85-102. 



Sperms are excellent material for 

 Electron Microscopy. See Schmitt, F. 

 O. (Biological Symposia, 1943, 10, 261) 

 and Scott, G. H. in McClung's Micro- 

 scopical Technique, 1950, p. 723. The 

 Keilin, D. and Hartres, E. F. (Nature, 

 1950, 165, 504) device of manifold in- 

 tensification of absorption spectra in 

 liquid air has been employed by Mann, 

 T. (Biochem. J., 1951, 48, 386-388) for 

 cytochrome determinations in sperm. 

 See Semen. 



Spermin Crystals are long prism-like forma- 

 tions produced in dried semen colored 

 brown or violet with iodine or potas- 

 sium iodide, also known as Boettcher's 

 crystals. 



Sphingomyelin, a compound of phosphoric 

 acid, a fatty acid, choline and sphingo- 

 sine without glycerol, soluble in ben- 

 zene, pyridine and hot alcohol and al- 

 most insoluble in ether, see Lipoids. 



Spirit Blue (CI, 689)— anilin blue alcohol 

 soluble, gentian blue 6B, light, Lyon 

 and Paris blues— A mixture of di- and 

 tri-phenyl rosanilin chlorides. Conn 



(p. 133) reports that it is a good stain 



for growing nerve fibers. 

 Spirit Indulin, see Indulin, spirit soluble. 

 Spirit Nigrosin R, see Indulin, spirit soluble. 

 Spirochaetales. The organisms of this 



group often require special methods for 



demonstration ; but within the gastric 



f lands of humans (Doenges, J. L., Arch, 

 'ath., 1939, 27, 469-477) dogs, cats, rats 

 and Macacus rhesus monkeys (Cowdry, 

 E. V. and Scott, G. H., Arch. Path., 

 1936, 22, 1-23) they can frequently be 

 seen in ordinary hematoxylin and eosin 

 preparations. Preparations of these be- 

 nign organisms are therefore easily 

 made and useful as showing intracellular 

 forms within parietal cells. For special 

 techniques see Treponema Pallidum, 

 Warthin-Starry method and Vincent's 

 Angina. 

 Spleen. Fixatives penetrate the spleen 

 poorly on account of the large amount 

 of blood in it. Consequently it is desir- 

 able to fix only thin slices of it, say 3-4 

 mm. thick. If the spleen is particularly 

 soft to begin with the slices will not hold 

 their shape and it may be necessary to 

 cut parallel to the surface and include 

 the capsule as a support. Direct ob- 

 servation of splenic venous sinuses 

 in vivo (Knisely, M. H., Anat. Rec, 

 64, 499-524; 65, 23-50; MacKenzie, D. 

 W., Whipple, A. O. and Wintersteiner, 

 M. P., Am. J. Anat., 1941, 68, 397-456). 

 Transplants into omentum (Holyoke, 



E. A., Am. J. Anat., 1940, 66, 87-132). 

 For vascular injections of Malpighian 

 bodies, see Nisimaru, Y. and Staggerda, 



F. R., J. Physiol., 1932, 74, 327-337. 

 See Kurlof Bodies. 



Spodogramme, term used bj' French his- 

 tologists for the mineral skeleton of 

 tissue revealed by Microincineration. 



Spore Stain, a modification of Dorner's. 

 Make thin film on slide. Cover with 

 blotting paper and add freshly filtered 

 Ziehl's carbol fuchsin. Steam 5-10 min. 

 on hot plate, the blotting paper being 

 moistened with the fuchsin. Decolor- 

 ize instantaneouslj' with 95% alcohol 

 and wash in water. Add drop of sat. 

 aq. nigrosine and spread thinly. Dry 

 quickly and examine. Spores red, other 

 parts of bacilli almost colorless against 

 dark background. Said to be simpler, 

 quicker than the unmodified Dorner's 

 method. It is recommended for Bacil- 

 lus megatherium, B. niger, B. cereus, 

 B. mycoides and some cultures of B. 

 subtilis (Snyder, M. A., Stain Techn., 

 1934, 9, 71-72). 



Stain heat fixed film with carbol - 

 fuchsin (see Acid Fast Bacilli). Rinse 

 quickly and difforentiate in 95% alcohol. 

 Wash in hot tap water and again rin.se 

 in alcohol. Counterstain for 2-5 min. 



