Crushed drop

Crushed drop - way observation of living organisms in the microscope. In the middle of the slide put a noose or a pipette drop of investigated material, her gently cover cover glass that liquid is formed of air bubbles. The drop must fill all the space between glasses l not extend beyond the edges of the glass cover. Sometimes, if the drug should be considered for a long time, edge cover glass pre-lubricated with vaseline. The drug can be painted, carefully adding loop dissolved dye. Cm. also Bacteriological examination, Microscopic techniques.

Crushed drop is a method of preparing drugs for microscopic study living objects. Applied in the study of bacteria, cells, tissue culture, protozoa, algae and other small organisms.
For preparation method crushed drops on the surface of clean, dry slides put a drop of water, physiological solution, or cultural liquid. Glass rod or bacteriological loop in a drop contribute a small amount of the studied culture and carefully distribute it in the liquid to obtain a homogeneous suspension. When working with tissue culture on a glass slide cause a drop of the suspension of cells in culture fluid. If a cell suspension is too thick, pre-prepare the working culture. This is usually to 4.5 ml of water, physiological solution, or environment for the growth of added 0.5 ml suspension of cells and carefully mix. This provides a tenfold dilution of the initial suspension. If necessary, you can get more high dilutions (1:100-1:1000, and so on); prepared drop serves a cover glass, avoiding air bubbles. If the liquid is at the edge of the glass cover, the excess of the environment, you can suck a narrow strip of filter paper.
Finished products considered in dry and immersion systems. To obtain the highest contrast apply or dark-field, phase-contrast microscopy. As this is often necessary dual immersion (the lens and the condenser), the thickness of the drug should not exceed 1,1-1,3 mm Unpainted organisms look under the microscope circled light or dark (depending on the focus) strip (line Veche)occurring at the border of refraction of the medium and body.
Besides studying unpainted bacteria, protozoa, and so on, method crushed drops allows to apply methods lifetime painting. As the dye is widely used by 0.1% aqueous solution of neutral red. Cm. also Microscopic techniques.