robert koch developed staining method for differentiating between groups of bacteria.
robert koch developed staining method for differentiating between groups of bacteria.
who developed staining method for differentiating between groups of bacteria?
robert koch
the work that gained gram an international reputation was his development of a method of staining bacteria, to make them more visible under a microscope. the stain later played a major role in classifying bacteria. gram was a modest man, and in his initial publication he remarked, "i have therefore published the method, although i am aware that as yet it is very defective and imperfect; but it is hoped that also in the hands of other investigators it will turn out to be useful." a gram stain is made using a primary stain of crystal violet and a counterstain of safranin. bacteria that turn purple when stained are called 'gram-positive', while those that turn red when counterstained are called 'gram-negative'.
hans christian gram
alcian blue () is any member of a family of polyvalent basic dyes, of which the alcian blue 8g (also called ingrain blue 1, and c.i. 74240, formerly called alcian blue 8gx from the name of a batch of an ici product) has been historically the most common and the most reliable member. it is used to stain acidic polysaccharides such as glycosaminoglycans in cartilages and other body structures, some types of mucopolysaccharides, sialylated glycocalyx of cells etc. for many of these targets it is one of the most widely used cationic dyes for both light and electron microscopy. use of alcian blue has historically been a popular staining method in histology especially for light microscopy in paraffin embedded sections and in semithin resin sections. the tissue parts that specifically stain by this dye become blue to bluish-green after staining and are called "alcianophilic" (comparable to "eosinophilic" or "sudanophilic"). alcian blue staining can be combined with h&e staining, pas staining and van gieson staining methods. alcian blue can be used to quantitate acidic glycans both in microspectrophotometric quantitation in solution or for staining glycoproteins in polyacrylamide gels or on western blots. biochemists had used it to assay acid polysaccharides in urine since the 1960s for diagnosis of diseases like mucopolysaccharidosis but from 1970's, partly due to lack of availability of alcian and partly due to length and tediousness of the procedure, alternative methods had to be developed e.g. dimethyl methylene blue (dmb or dmmb) method.
alcian blue stain