A note about these archived materials
This page preserves study notes prepared during earlier coursework. It has not been comprehensively revised to reflect current clinical, scientific, testing, or regulatory standards. It is provided for educational and historical reference only—not as medical advice, a treatment guide, or a substitute for current course materials and authoritative health guidance.
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All of the information which is here came from other websites. The answers are correct as far as I know. If you find anything that seems incorrect, I would appreciate hearing about it so that I can make corrections.
| Purpose of Staining: increases Contrast & Resolution
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Provide contrast (easier to see cells against background (slide)
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| Simple Stain |
1 stain used: Basic (OH-) or acidic (H+) (BOOK -ONLY BASIC DYES)
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NO HEAT SETTING- Use dye 30-60 sec and rinse
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| Basic Stain
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(+) Cationic chromophores
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Colored part has a (+) charge: Methylene blue(+) and chloride(-)
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| Crystal violet stains cells NOT CAPSULES |
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stain acidic structures / best under basic high Ph(Most cells have a natural (–) negative charge à Attract Stain)
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| BASIC stain colors à |
| Direct Stain |
Simple Procedure – BASIC stains used / Stain organism Directly |
| Acidic Stain
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(-) Anionic Chromophores
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Colored part Negative (-) charge (stain repelled by cells)
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Stain alkaline structures / work best in acidic low Ph
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Background (Slide) is stained / cells remain CLEAR
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Acidic stain colorsà |
| Negative Stain
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NO heat fixing
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Acidic Stains Used:
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1. colors background
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2. Leaves cells clear
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| Capsule staining:
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+ Positive stain colors the body
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– Negative stain colors the background
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Treponema pallidum – will not stain directly
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Causative agent of syphilis
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