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US 4,225,669 AGranted
Staining and analysis of bacteria
OwnerJoseph L. Melnick, Craig Wallisinventors
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OwnerJoseph L. Melnick, Craig Wallisinventors
Estimating the term…
A bacterial staining composition and methods of analysis of both gram-negative and gram-positive bacteria are disclosed. The composition comprises a chelating agent and a basic dye, both of which are operative at a pH above about 7.0. Bacterial staining may be effected by contacting either concentrated or fluidly suspended bacteria with the composition at a neutral or basic pH. Bacteria stained with the composition and concentrated by filtration, centrifugation or the like are readily visible and their presence in a specimen may, thus, be rapidly detected. The gradations of color of the stained, concentrated bacteria correspond to the number of bacteria and semi-quantitative analysis of the bacteria may be effected by comparison with a standard. Differentiation of gram-negative and gram-positive bacteria may be accomplished by treating the stained bacteria with an organic acid wash having a pH of about 2.5 to 2.6. Such a wash completely decolorizes only stained gram-positive bacteria. Finally, a method for determining bacterial susceptibility to antimicrobial agents is provided which comprises incubating bacteria with an antimicrobial agent, staining the bacteria and thereafter comparing the color gradation of the stained, concentrated bacteria with a control or standard.
A composition for staining bacteria at a pH above about 7.0 comprising:
A method of staining bacteria which comprises contacting the bacteria at a pH at or above about 7.0 with a composition comprising a chelating agent operative at a basic pH and a dye capable of staining bacteria at a basic pH.
A method for detecting bacteria in fluids comprising:
A method for quantitatively detecting the presence of bacteria in a fluid specimen which comprises:
A method for differentiating gram-negative and gram-positive bacteria which comprises:
A method for determining the susceptibility of bacteria to antimicrobial agents which comprises:
A combination for detecting bacteria in fluids comprising:
Dependencies are inferred from the claim text.