Hello, a metachromatic stain refers to a dye that is usually heterochromatic and said heterochromacy depends on how far together or apart the dye molecules are. For example, in the Wright or Giemsa stain, which are the metachromatic stains par excellence, the closer the molecules are, the darker they look and the further apart they are, the pinker or bluer they look, depending on the case, I am sending you a photo so that you see the difference If you need more information, I can gladly provide it. Greetings.

Hi, some practical histology hints can be found here: https://nios.ac.in/media/documents/dmlt/HC/Lesson-12.pdf. Greetings.

Very good

Hello. Metachromatic staining is characterized by the fact that a single dye produces different colors according to the characteristics of the cell wall in different tissues, that is, they act as a double or triple differential stain. For plant tissues are metachromatic; Brilliant Crescilo blue (Pérez and Tomasi, 2002) that produces an important variation of colors according to the tissue in question. Toluidine blue and crescyl violet are also metachromatic. The latter colors the non-lignified walls and the bluish-green lignified secondary walls red-violet (D'Ambrogio de Argueso. 1986).

D´Ambrogio de Argüeso, 1986. Manual de técnicas en Histología vegetal. Editorial Hemisferio Sur. Buenos Aires.

Pérez, A.N. & Tomasi V.H. 2002. Tinción con azul brillante de cresilo en secciones vegetales con parafina. Boletín de la Sociedad Argentina de Botanica

Hope this is useful. Best regards

Dear Saroj Kumar Khan ,

your Question title should have been

„Albert Stain and interpretation of outcome –with reference to metachromasia of ‚granules‘?“

Interesting, that ‚Albert stain‘ I was not able to find in one of the ‚famous‘ Handbooks/Method Collections on ‚Histological and Special Tissue – Bio-Material Staining‘ I used to learn and read during my active professional time (e.g. Conn, Bancroft, Luna, etc.)

Bancroft John D. and Marilyn Gamble (Eds, Churchill Livingstone-Elsevier, 2008) in their book ‚Theory and Practice of Histological Techniques‘ report only a ‚Papanicoloau-stain‘ for a short gram-negative (sic!) bacillus, namely ‚Corynebacterium vaginale‘.

Since I was not aware of such an "Albert stain", I got interested in a clarification, what was meant with your question and tried to dig data….

So I had to use Google a bit and (easily, keyword/search phrase "Albert stain") found the following about that ‚ominous‘ „Albert Stain“,

== which „distinctly identifies metachromatic granules that are found in Corynebacterium diphtheriae (*1)“

- a typical two-step staining procedure comprised of 2 solutions, A and B, to be applied on slides of a smear preparation for „localization“ / making evident ‚metachromatic granules‘ , one type out of diversely colored components ( i.e. e.g., „round-shaped blue-black dots at the bottom of L-shaped or V-shaped green Bacilli“ (1*) after the staining procedure) is applied to get an evidence of an infection with Corynebacterium diphteriae ==

The search leads you quite fast to special primary and secondary literature dealing with the ‚problem‘, also especially regarding "metachromasia".

Especially one article seems to answer most if not all of your question(s):

(*1) Albert Staining- Principle, Reagents, Procedure, Results, Interpretation

February 1, 2022 by Faith Mokobi

Edited By: Sagar Aryal

Albert Staining- Principle, Reagents, Procedure, Results, Interpretation

(=URL:https://microbenotes.com/albert-staining/)

Table of Contents

· Objective

· Principle of Albert Staining

· How are these solutions prepared?

· Procedure of Albert Staining

· Result

· Interpretation of Albert Staining

· Applications of Albert Staining

· Limitations of Albert Staining

· References

Just for rapid information of the interested reader:

(Quote:)

„Albert stain distinctly identifies metachromatic granules that are found in Corynebacterium diphtheriae.

Corynebacteria are gram-positive, non-spore forming, non-motile bacilli that contain metachromatic (Volutin) granules which are intracellular inclusion bodies, found in the cytoplasmic membrane of some bacterial cells for storage of complexed inorganic polyphosphate (poly-P) and enzymes. When these granules are subjected to stain with methylene blue dye, they appear reddish-purple color and not the blue dye.

The most common Corynebacterium is Corynebacterium diphtheriae, that caused diphtheria, a nasopharyngeal infection (affecting the nasal, throat) that can also affect the skin, after bacterial colonization and infection.

Basically, this bacteria is initially cultured in selective media either a Loeffler agar or Mueller-Miller tellurite agar, or Tinsdale tellurite agar, and its colonize isolated to prepare liquid culture that is then used for staining. Albert stain only acts as a confirmatory stain for the bacteria. Being a differential stain, it can only stain volutin granules, hence bacteria without these granules can not be stained nor identified with this technique.“

Principle of Albert Staining

Albert staining technique aims at detecting the presence of metachromatic granulated bodies of Corynebacterium diphtheriae. Albert stain is made up of two staining solutions; designated as Albert Solution 1 and Albert Solution 2, their compositions being;

Albert Solution 1:

· toluidine blue, malachite green, glacial acetic acid, and alcohol

Albert solution 2:

· Iodine and Potassium iodide in water

To use Albert’s staining solutions, each of the two solutions must be prepared effectively with the right percentages of components in order to demonstrate the granules with the right color after staining.

Albert staining solution 1 acts as the staining solution while Albert solution 2 acts as the mordant, i.e an ion element that binds and holds a chemical dye, to make it stuck on the micro-organism.

Follows: How are these solutions prepared – Procedure of Albert’s staining – Result: >The metachromatic granules stain bluish black while the rest of the microbial cell stains green.

Dimitrolos Krajci and

Saroj Kumar Khan ,

thank you for including the URL [ to 'Metachromatic Staining", Chapter 12] for an interesting explanation what

"metachromasia" is and how it can / will be achieved.....

Just to complete information on that particular document (since the SOURCE is NOT mentioned in the PDF):

>NIOS.AC.IN< is the website of the NATIONAL INSTITUTE of OPEN SCHOOLING [https://nios.ac.in/], an autonomous Institution under Ministry of Education, Government of India - the largest Open Schooling System in the World. Unfortunately a bibliography of the primary source (author, year of publishing) could not be assessed (perhaps the pdf is hidden in the "Online Course Material"-Section ...but this is rather my guessing.

Regards, W.H.M.