| 释义 |
over-ˈstain, v.
[over- 8, 27.]
1. trans. To cover with a stain or stains.
1595Shakes. John iii. i. 236 Our hands..besmear'd and ouer-staind With slaughters pencill.
2. Biol. To stain (tissue) excessively, usu. in order that certain parts may be differentiated by selective removal of some of the stain; also absol.
1885C. O. Whitman Methods of Research in Microsc. Anat. ii. 39 If by any chance the sections are over-stained, the superfluous color may be extracted by a brief sojourn in very dilute ammonia. Ibid. 48 Diffuse staining may generally be avoided by first overstaining and then withdrawing the color to any desired extent by means of alcohol. 1935Kingsbury & Johannsen Histol. Technique 38 In regressive staining the tissue is over-stained and the excess of stain removed by the application of a differentiator. Ibid. 40 The rule is to over-stain and watch the differentiation carefully with the microscope. 1971A. Lamela Introd. Med. Lab. Methods xxiii. 238 The tissue is over-stained and then decolorized until the correct depth of color is obtained.
Hence over-ˈstaining vbl. n.
1885C. O. Whitman Methods of Research in Microsc. Anat. ii. 42 Minot's picric-acid carmine..gives a stronger differential coloring than Ranvier's picro-carmine; but over-staining must be most carefully avoided. 1929C. E. McClung Handbk. Microsc. Technique i. 23 Regressive stains..are allowed to act until overstaining is accomplished, after which the desired degree of differentiation is brought about by removal of the excess coloration. |