The usefulness of alkaline solutions for clearing the uterus and staining implantation sites in rats.
The alkaline solution method for detecting uterine implantation sites (metrial glands or spots after delivery), which indicate the position of the embryo, was compared with conventional methods using Turnbull blue (Salewski's technique) and benzyl benzoate (Orsini's technique) in rats. When rat uteri were immersed directly in 2% sodium hydroxide [NaOH], potassium hydroxide [KOH] solution or one of several other alkaline solutions for one hour, the uteri were cleared. Then the metrial glands could be observed without further staining, and the spots after delivery with further staining. After alkaline treatment, unstained metrial glands appeared as yellowish-white degenerated masses and stained spots after delivery appeared as yellowish-brown patches covered with yellowish-white lumps. These yellowish-brown or yellowish-white sites were probably stained by the iron in hemosiderin deposits in the placental scar or in a vestige of the metrial glands left over from pregnancy. Formalin-fixed uteri were not cleared by immersion in a high concentration of NaOH, KOH or other alkaline solutions, but the spots after delivery were stained by this treatment. Turnbull blue did not stain the metrial glands, which contain no iron. Benzyl benzoate cleared fixed or unfixed uteri and allowed observation of the metrial glands and spots after delivery although the entire process required a few days and the specimens became hard and shriveled. The best and most convenient solution for clearing the rat uterus and for staining implantation sites was 2% NaOH or KOH.
Yamada
T
T
Research Center, Taisho Pharmaceutical Co., Ltd., Saitama-ken, Japan.
Ohsawa
K
K
Ohno
H
H
D000818:Animals; D001565:Benzoates; D010064:Embryo Implantation; D005260:Female; D006878:Hydroxides; D011188:Potassium; D017680:Potassium Compounds; D051381:Rats; D012972:Sodium Hydroxide; D012996:Solutions; D013194:Staining and Labeling / Q000379:methods*; D014599:Uterus
D001565:Benzoates; D006878:Hydroxides; D017680:Potassium Compounds; D012996:Solutions; D012972:Sodium Hydroxide; C006723:benzyl benzoate; D011188:Potassium; C029943:potassium hydroxide