Processing Techniques Flashcards
7 cards from real CTBS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Processing Techniques flashcards as text
Which factor most significantly affects the residual moisture content of a lyophilized bone allograft?
Answer: The duration and temperature of the secondary drying phase
The secondary drying (desorption) phase of lyophilization, which removes bound water, has the greatest effect on final residual moisture content of the product.
When processing soft tissue allografts (e.g., tendons, ligaments), what is the primary function of low-dose gamma irradiation (< 20 kGy)?
Answer: To reduce bioburden without significantly compromising mechanical properties
Low-dose gamma irradiation is used to reduce microbial bioburden while minimizing radiation-induced damage to the collagen structure and mechanical integrity of soft tissue allografts.
What is the purpose of adding a radioprotectant such as ascorbic acid or mannitol during irradiation of soft tissue allografts?
Answer: To scavenge free radicals generated by radiation and reduce collagen damage
Radioprotectants like ascorbic acid and mannitol are free radical scavengers that neutralize reactive oxygen species produced by radiation, thereby reducing radiation-induced collagen degradation.
During aseptic tissue processing, which environmental classification is required for the critical zone where tissue is exposed?
Answer: ISO Class 5 (Class 100)
ISO Class 5 (equivalent to Class 100) clean room conditions are required in the critical zone where tissue is directly exposed during aseptic processing to minimize particulate and microbial contamination.
What processing step is used to remove lipids from bone allografts, and why is it performed?
Answer: Defatting with organic solvents such as chloroform-methanol; improves handling and reduces inflammatory response
Defatting with organic solvents like chloroform-methanol removes bone marrow fat, which improves handling characteristics, reduces rancidity during storage, and decreases inflammatory response after implantation.
Which validation study is required to demonstrate that a processing method effectively inactivates enveloped and non-enveloped viruses in tissue?
Answer: Viral clearance validation study using surrogate viruses
Viral clearance validation studies use surrogate (model) viruses to demonstrate that the processing steps achieve adequate log reduction of both enveloped and non-enveloped viral contaminants.
What is the recommended maximum residual moisture content for lyophilized bone allografts to ensure long-term stability at ambient temperatures?
Answer: ≤ 6%
Lyophilized bone allografts should have a residual moisture content of ≤6% to prevent microbial growth and chemical degradation during ambient temperature storage.