MACROPHAGES 



143 



MAGNESIUM 



the reticulo-endothelial system. Al- 

 most any method of exposure to rela- 

 tively non-toxic, finely particulate 

 matter is sufficient to bring them out. 

 The simplest way is to inject mice with 

 trypan blue as described under Vital 

 Staining and to look for the macro- 

 phages in spreads of Loose Connective 

 Tissue. Another method, used by 

 Maximow, is to give rabbits intra- 

 venous injections of saccharated iron 

 oxide or India ink and to examine blood 

 from right ventricle in smears (see 

 Cowdry's Histology, p. 69). Lines of 

 division between macrophages and 

 monocytes, if they exist, are difficult 

 to establish. Supravital staining with 

 Neutral Red and Janus Green is useful 

 to demonstrate neutral red granules 

 and mitochondria respectively. 

 Madder Staining of bone. Madder is a red 

 dye, prepared from the plant Ruhia 

 Tinclorum which has been used for 

 thousands of years. It is perhaps the 

 first dye to be used in camouflage in war. 

 With its help Alexander defeated the 

 Persians by staining the clothing of his 

 Greek soldiers red, each garment in a 

 difi'erent part so that the Persian leaders 

 at once concluded that all they had to 

 cope vvith w^as an already well damaged 

 army. (Leggett, W. F., Ancient and 

 Medieval Dyes. Brooklvn: Chemical 

 Publishing Co., Inc. 944, 95 pp.) 



Alizarin and purpurin, formed from 

 madder, are now made sj^nthetically. 

 Madder should be employed for the 

 vital staining of growing bone as de- 

 scribed by Macklin (C. C., Anat. Rec, 

 1917, 12, 403-405; J. Med. Res., 1917, 

 36, 493-507). Young rats are suggested 

 as material. Each should eat 1-5 gms. 

 of madder, thoroughly nuxed with its 

 food, daily. The calcium deposited in 

 the growing bone while madder is thus 

 made available in the circulation is 

 colored red. Staining is noticeable 

 after 1 day but the feeding should be 

 continued for a week or more. 



The ventral ends of the ribs and the 

 epiphj^seal lines of long bones are most 

 intensely colored. The bones selected 

 are fixed in 10% neutral formalin, 

 washed and cleaned in water, dehy- 

 drated thoroughly in alcohol, placed in 

 benzene for 24 hrs., cleared in oil of 

 wintcrgreen by the method of Spalteholz 

 and examined with binocular microscope 

 as whole objects. 



Chemistry of madder staining is dis- 

 cussed by Dr. Richter (Biochem. J., 

 1937, 31, 591-595). The substance giv- 

 ing the intense carmine red color is 

 apparently purpurin carboxylic acid. 

 IVIadder is one of the most classical of 

 stains. Its history extends back through 



the centuries and has been well reviewed 

 by F. T. Lewis (Anat. Rec, 1942, 

 83, 229-253). See Line Test. 



Magdala Red (CI, 857) — naphthalene pink, 

 naphthalene red, naphthylamine pink, 

 Sudan red — According to Conn (p. 102) 

 this basic naphtho-safranin differs from 

 commercial magdala red which is an 

 acid dye belonging to an entirely dif- 

 ferent group. He calls attention to its 

 use by Kultschitzky, N., Arch. f. 

 Mikr. Anat., 1895, 46, 673-695) in stain- 

 ing elastic tissue of the spleen. Used 

 as a fluorochrome for Lipids. 



Magenta, see Basic Fuchsin. 



Magenta II is triamino ditolyl-phenyl- 

 methane chloride probably present in 

 most samples of Basic Fuchsin. See 

 Pararosanilin (Mtigenta O), Rosanilin 

 (Magenta I) and New Fuchsin (Magenta 

 III). 



Magnafiux is a useful instrument employed 

 in the FBI Laboratory to detect the 

 occurrence of small cracks and defects 

 in the surface of metallic objects. 

 When, for example, a magnetizable 

 object is placed in a magnetic field, 

 created by the magnafiux, the field is 

 distributed throughout the m.etal if it 

 is sound. Otiierwise, magnetizable pig- 

 ments become oriented around the 

 breaks in the surface indicating their 

 location (Hoover, J. E., Scientific 

 Monthly, 1945, 60, 18-24). Obviously 

 metallic laboratory equipment can be 

 tested in this way. 



Magnesium, Titan yellow method for de- 

 termination of small amounts in body 

 fluids (Haurv, V. G., J. Lab. & Clin. 

 Med., 1938, 23, 1079-1084). 



Methods for detection in plant cells 

 (Broda, B., Mikrokosmos, 1939, 32, 

 184). (1) Triturate 1 part quinalizarin 

 with 5 parts sodium acetate crystals. 

 Make to fresh 0.5% solution in 5% aq. 

 NaOH. Addition of 1-2 drops to paraf- 

 fin section, then 1-2 drops 10% NaOH 

 results after some hours in blue stain. 

 (2) Add to paraffin section 1-2 drops 

 0.2% aq. Titan yellow, then 1-2 drops 

 10% NaOH gives rise to brick red stain 

 of magnesium. (3) Add to paraffin sec- 

 tion 0.1% aq. azo blue. Gives, without 

 the NaOH, a violet stain of magnesium. 

 An attempt should be made to adjust 

 these techniques to human tissues in 

 which a magnesium salt has been 

 injected. 



By means of a specially constructed 

 electron microscope Scott and Packer 

 (G. H. and D. M., Anat. Rec, 1939. 

 74, 17-45) have accurately localized 

 magnesium and/or calcium in muscle. 

 The method can be extended to other 

 tissues and perhaps to other minerals. 

 Histospectrography gives diita on the 



