Appearance Purple powder | ||
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What does bromocresol purple mean
Bromocresol purple (BCP) or 5′,5″-dibromo-o-cresolsulfophthalein, is a dye of the triphenylmethane family (triarylmethane dyes) and a pH indicator. It is colored yellow below pH 5.2, and violet above pH 6.8. In its cyclic sulfonate ester form, it has a pKa value of 6.3, and is usually prepared as a 0.04% aqueous solution.
Contents
- What does bromocresol purple mean
- Indicador de ph p rpura de bromocresol ph indicator bromocresol purple
- Uses
- pH Indicator
- References
Indicador de ph p rpura de bromocresol ph indicator bromocresol purple
Uses
Bromocresol purple is used in medical laboratories to measure albumin, although it is no better in this role than the older method using bromocresol green. In microbiology, it is used for staining dead cells based on their acidity, and for the isolation and assaying of lactic acid bacteria.
In photographic processing, it can be used as an additive to acid stop baths to indicate that the bath has reached neutral pH and needs to be replaced.
Bromocresol purple milk solids glucose agar is used as a medium used to distinguish dermatophytes from bacteria and other organisms in cases of ringworm fungus (T. verrucosum) infestation in cattle and other animals.
pH Indicator
Similar to bromocresol green, the structure of bromocresol purple changes with pH. The low pH (acidic) form is yellow in solution and the high pH (basic) form is purple; the sultone (cyclic sulfonic ester) is the acidic form in the following equilibrium.