Pacini's Fluid

PACINI'S FLUID (Pacini) is used for certain types of hematological research, especially where it is necessary to subject blood to dilution without damaging the red blood cells. For example, in performing clinical blood analysis (counting red blood cells) or in forensic practice when detecting traces of blood in dried spots. P. f. consists of mercuric chloride 1 g, NaCl 2 g, glycerin 26 cm³ and water 226 cm³. Due to the fact that the mercuric chloride included in its composition ensures the preservation of red blood cells for a long time, P. f. can be successfully used for diluting blood (in a mixer) necessary for counting red blood cells. In this sense, it can compete with physiological solution and Hayem's fluid (it should however be noted that the latter two solutions are more commonly used). In forensic practice, P. f. of the following composition is used: mercuric chloride 1 g, NaCl 2 g, glycerin 100 cm³ and water 300 cm³. Here it is used in cases where traces of blood are very old or the blood has dried so much with the tissue that it cannot be soaked with physiological solution. In these cases, particles of the suspicious spot are scraped off or the tissue on which it is located is torn apart, and P. f. is applied to them (on a slide). Mostly in this way it is possible to isolate red blood cells.