Preparing
a smear for staining. This procedure is used for all stains
except the Negative Stain.
1.
Sterilize your loop before and after use. Be sure to get the entire
wire red hot. |
 |
| 2.
Prepare a smear |
| a.
Place
a loopful of water on the slide if you have a solid culture |
b.
A
loopful of liquid culture can be place directly on the slide. |
 |
 |
|
| 3.
Let
the smear dry completely in the air. Do not apply heat because this
can distort the cells. |
 |
| 4.
Fix the smear. |
| a.
Smears
can be heat-fixed by quickly passing the slide through a flames,
three times. |
b.
Another
method of fixing the smear is to cover it with methyl alcohol
for 1 min. |
 |
 |
| |
|
| 5.
Stain the smear. Gram stain. Acid
fast stain. Structural stains. |
|
| |
|
| 6.
Observe the slide under low and high-dry lenses to center and focus
the image. Place a drop of oil directly on the stained smear (no cover
slip). Turn the oil immersion lens into position and observe the cells. |
 |
BIOL
240 visual lab guide
