Which brand is good for chemical analysis instruments?
Glutaraldehyde is a five carbon aldehyde with two aldehyde groups. The formula is $C_5H_8O_2$, and the molecular weight is 100. Electron microscopic fixation is usually diluted with commercially available 25% glutaraldehyde water solution to the desired concentration. Its pH is 4.0$sim$5.0. Oxygen, high temperature, neutral or alkaline pH can make glutaraldehyde polymerization, lose aldehyde group, and reduce cross-linking effect, so usually this kind of liquid should be kept at low temperature.
In addition, when the glutaraldehyde storage time is too long, the pH value will be reduced, the color yellow, the fixed potency will be greatly reduced. If the glutaraldehyde pH value drops below 3.5 or contains other impurities, it must be purified before it can be used. Glutaraldehyde has a hardening effect on the skin, but it is less volatile than formaldehyde. It is best to operate in a fume hood.
Unlike glutaraldehyde, formaldehyde reacted with DNA and nuclear proteins, but these reactions were partially reversible. In addition, the ability of formaldehyde to fix lipids is not strong enough to function as proteins linked to lipids.
