Lead fixatives are used for preserving which substances?

Lead fixatives are used for preserving which substances?

• A. Acid mucopolysaccharides
• B. Nucleic acids
• C. Proteins
• D. Lipids

Answer: (A)

Lead fixatives are used for preserving acid mucopolysaccharides (glycosaminoglycans) because lead ions form insoluble complexes with sulfated carbohydrate chains, stabilizing these highly hydrated polymers during processing. This makes mucopolysaccharide-rich areas like cartilage matrix, basement membranes, and mucus better preserved. Nucleic acids, proteins, and lipids don’t benefit as much from lead fixation—nucleic acids are better preserved with other methods that protect DNA/RNA, proteins are generally best preserved with formaldehyde-like crosslinking, and lipids require lipid-specific fixatives.

Lead fixatives are used for preserving acid mucopolysaccharides (glycosaminoglycans) because lead ions form insoluble complexes with sulfated carbohydrate chains, stabilizing these highly hydrated polymers during processing. This makes mucopolysaccharide-rich areas like cartilage matrix, basement membranes, and mucus better preserved. Nucleic acids, proteins, and lipids don’t benefit as much from lead fixation—nucleic acids are better preserved with other methods that protect DNA/RNA, proteins are generally best preserved with formaldehyde-like crosslinking, and lipids require lipid-specific fixatives.