Schwyn and Neiland (8) developed a universal siderophore assay using chrome azurol S (CAS) and hexadecyltrimethylammonium bromide (HDTMA) as indicators. HDTMA has a moderate health and contact rating. Appropriate personal protective equipment should be used. The CAS/HDTMA complexes tightly with ferric iron to produce a blue color.

2020年12月4日 · Modified CAS-Agar Plate Assay for Detection of Siderophore Producing Fungi and Bacteria: The concentration of HDTMA and CAS is crucial for siderophore medium preparation. The lower concentration leads to precipitation of the blue dye and higher concentration may turn toxic to all organisms.

2011年5月19日 · We describe the CAS-agar plate assay as a quantitative methodology, which make it possible to select and evaluate the siderophore production by several microorganisms (fungi and bacteria ...

2007年7月1日 · In this work, the popular CAS assay for siderophore detection, based on the utilization of chrome azurol S, was redesigned and optimized to produce a new, fast, non-toxic, and easy method to determine a wide variety of microorganisms capable of siderophore production on a solid medium.

目前，常用的铁载体检测方法为Schwyn和Neilands发明的通用CAS琼脂平板法，当细菌产生的铁载体与由铬天青S（CAS）、十六烷基三甲基溴化铵（HDTMA）、铁离子组成的蓝色复合物结合后，会夺走铁离子，使细菌周围的培养基颜色由蓝色变为橘黄色，出现铁载体分泌圈 ...

2001年2月1日 · We developed a new method named ‘CAS agar diffusion (CASAD) assay’, by modifying the classical CAS plate and liquid assays, that can quantitatively measure total siderophores existing in any biological fluids.

2024年6月11日 · The simple double-layered CAS agar (SD-CASA) assay was developed as a quantitative, low-cost methodology to screen potential biocontrol microorganisms based on their siderophore production. This modified CAS assay involved the use of paper-disc agar diffusion to inoculate a specific amount of bacteria suspension onto CAS agar plates.

Among the total of 40 isolates obtained, only five were able to produce siderophores by the CAS agar plate assay method. The production of an orange or a yellow hallow zone around a colony indicated that it is a siderophore producer. The present study provides a detailed protocol to prepare the CAS agar without any difficulty.

2001年2月1日 · We developed a simple and universal method, by modifying the universal CAS (Chrome azurol S) assay, measuring siderophores in various biological fluids. We named the assay as CAS agar diffusion (CASAD) assay. CAS plate devoid of nutrients was prepared by using Bacto-agar (1.5%, w/v) as a matrix.

CAS（Chrome azurol S）检测液是由铬天青（chrome azurol sulphonate, CAS）、溴化十六烷基三甲铵 （hexadecy- ltrimethyl-ammonium bromide, HDTMA）和铁离子组成的一种复合物，呈亮蓝色。当蓝色检测平板中的铁离子被微生物分泌的嗜铁素夺走时，即可在微生物生长的菌落周围形成 …