Common name: Gram stain
English name: Gram Stain
Single bottle (box) Packing specification: 100ml
Set (box) Packing specification: 4×100ml
Smear staining for bacteria or fungi.
Gram staining is a method of differential staining widely used in bacteriology. It can be used for specimen smear or colony smear. After staining, the bacteria form a sharp contrast with the environment, and the morphology, arrangement and some of the bacteria can be clearly observed. These structural features are used for clinical classification and identification. The staining results divided the bacteria into two major categories: Gram-positive bacteria (purple) and Gram-negative bacteria (red). Gram-positive bacteria have thicker cell walls, more peptidoglycan network layers and dense cross-linking. After Gram staining, crystal violet and iodine complexes can be firmly retained in the wall, which is not easily removed by decolorizing liquid. It is still purple; Gram-negative bacteria have a thin cell wall, a high lipid content in the outer membrane layer, a thin peptidoglycan layer and poor cross-linking. After the decolorizing agent, the lipid-based outer membrane rapidly Dissolved, thin and loose peptidoglycan network can not block the dissolution of crystal violet and iodine complex, so it is still colorless after decolorization by decolorizing solution, and then counterstained with sand yellow solution, the gram-negative bacteria are red.
|Reagent composition||Main ingredient|
|Crystal Violet||Gentian violet , Ethanol|
|Iodine solution||Potassium iodide , iodine|
|Safranin Solution||Safrani , Ethanol,
5 ° C ~ 30 ° C protected from light, valid for 24 months.
The original packaging does not open the dyeing liquid for a period of 24 months. The opened dyeing solution is recommended to be used within 6 months after opening. After each use, the cap should be tightened in time to avoid evaporation or deterioration.
Care must be taken when smearing, and the smear is thin and uniform. The prepared smear should be naturally dry. When fixing with heat, the fixing temperature should not be too high. The back of the slide should not be hot to the back of the hand. Otherwise, the bacterial morphology may affect the observation.
1. Add gentian violet liquid for 10 seconds, wash with water, dry;
2. Dyeing with iodine solution for 10 seconds, washing with water, drying;
3. Decolorize the solution for 10-20 seconds, wash with water, dry;
4. Finally, add the yellow solution of the solution to the dyeing solution for 10 seconds, and wash it with water;
5. Wait until dry, microscopic examination.
Explanation of test results
Gram-positive bacteria are purple; Gram-negative bacteria are red.
Limitations of inspection methods
There is a possibility of false negatives when using smears of old specimens.
1. The dyeing time should be adjusted according to what kind of specimen, smear thickness, etc.; when dyeing gynecological leucorrhea smear, the dyeing time should be slightly extended (not less than 10 seconds) to obtain better dyeing effect.
2. If the smear is too thick, the decolorization time is insufficient, and the long time of gentian violet staining may lead to false positive results; excessive heat fixation of bacterial smears, too long bacterial culture time, excessive discoloration, etc. may lead to false negative results. .
3. When the room temperature is too low in winter, the dyeing time should be extended appropriately.
4. Try to avoid high and low temperature environment and direct sunlight when storing reagents.
5. After the reagents are used up, please cover them quickly to avoid evaporation.
6. This product should be used by professionals and the interpretation of the results.
7. Read the instruction manual carefully before use, use it within the validity period, and do personal protection.
8. Dispose of waste according to the requirements of the hospital or environmental protection department after use.
9. The production date, production batch number and expiration date are shown in the outer packaging.