Brilliant Blue G is triphenylmethane dye that was developed for use in the textile industry but is now commonly used for staining proteins in analytical biochemistry. The Bradford assay is a standard, rapid dye-binding assay that uses Brilliant Blue G to quantify the amount of protein in a solution. Brilliant Blue G also acts as a selective inhibitor of the P2X purinoceptor channel P2X7 (IC50s = 10.1 and 265 nM for rat and human P2X7, respectively). In mice, it inhibits interleukin-1β expression and reduces neurological injury secondary to traumatic brain injury. Brilliant Blue G was used to prepare the protein reagent for the determination of protein content of the collagenase enzyme isolated from fish waste. It may be employed as a stain for the internal limiting membrane (ILM) for the macular hole (MH) and epiretinal membrane (ERM) surgery.

Trypan blue (trade name MembraneBlue, VisionBlue) is a vital stain used to selectively color dead tissues or cells blue. Live cells or tissues with intact cell membranes are not colored. Since cells are very selective in the compounds that pass through the membrane, in a viable cell trypan blue is not absorbed; however, it traverses the membrane in a dead cell. Hence, dead cells are shown as a distinctive blue color under a microscope. Since live cells are excluded from staining, this staining method is also described as a dye exclusion method. This dye may be a cause of certain birth defects such as encephalocele. Trypan blue is commonly used in microscopy (for cell counting) and in laboratory mice for assessment of tissue viability. The method cannot distinguish between necrotic and apoptotic cells. Trypan blue is also used in ophthalmic cataract surgery to stain the anterior capsule in the presence of a mature cataract, to aid in visualization, before creating the continuous curvilinear capsulorhexis.

Tetraamminecopper sulfate is a dark blue crystalline solid with a faint odor of ammonia. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. Used as a pesticide and fungicide, to print fabrics (especially in calico finishing), and to make other copper compounds.

Methylene blue, also known as methylthioninium chloride, is a medication from WHO's list of essential medicines. Upon administration, methylene blue is converted to leukomethylene blue by erythrocyte methemoblobin reductase in the presence of NADPH. Leukomethylene blue than reduces methemoglobin to oxyhemoglobin, thus restoring oxygen carrying capacity of the blood. Methylene blue is also used as a dye for various diagnostic procedures, for treatment of ifosfamide toxicity and for in vitro staining. Historically, it was used as a photosensitizer for photodynamic therapy for topical treatment of dermatologic or mucocutaneous infections, as an antidote for cyanide poisoning, but these applications are no longer approved. Methylene blue is investigated in clinical trials for treatment of septic shock and Alzheimer's disease.

Ferric Ammonium EDTA Solution is normally used as a photographic chemical for a bleaching agent in the process of colour washing. It is also used as a complexing, and oxidizing agent & as a fertilizer and catalyst. EDTA acid are colourless, water-soluble solid that are widely used to dissolve scale. The usefulness of these ammonium salts arise because of its role as a chelating agent, i.e. its ability to "sequester" metal ions such as Ca2+ and Fe3+.

L-MTX is a second-generation tau protein aggregation inhibitor. It acts by reducing levels of aggregated or misfolded tau proteins, which are associated with the progressive neurodegeneration. It is currently under development for the treatment of Alzheimer’s disease.