Lecture 15: Gamete and Embryo Cryopreservation Flashcards
(55 cards)
Sperm can be frozen “INDEFINTELY” with cryoprotectant and stored in liquid nitrogen?
T/F
True
When was the first human SPERM cryopreservation?
When was the first baby born from frozen sperm?
- 1950’s
- 1953
What reasons to people freeze sperm in a sperm bank?
6
- Cancer-related therapy
- Testicular or Prostate surgery
- Vasectomy
- High-risk occupational exposure
- IUI or ART
- Varied time intervals of partners
What is “Sperm Banking?”
Saving sperm for your own future use
What is “Sperm Donation?”
Allow your sperm to be used by someone else
What reasons do people use frozen sperm from donations?
3
- Used by couples who have male infertilities
- Couples who have genetic abnormalities
- Single Women or Lesbians
What are the qualifications of donor sperm?
3
- Around ages 20-39
- Pyschological, genetic and medical screening
- STD screening
Donor sperm are frozen and quarantined for ___ months to permit _______ of STD’s
- 6
- re-testing
What are the financial compensations for sperm donation?
- $125 per donation
- Donate 2-3 times per week (24-48 abstinence period)
- Expected Participation is 9-12 months
- 1099 tax form
What is “cryopreservation?”
Process where cells or whole tissues are preserved by cooling to low sub-zero temps in liquid nitrogen
What is the temperature they keep the sperm in liquid nitrogen?
- (77K)
- (-196 C)
- (-321 F)
What 2 ways are cells protected by freezing injury?
- Controlled cooling (& thawing) rate
- Cryoprotectants (a form of anti-freeze)
What is the Slow Freezing Danger zone between?
- 0 to -60 C
What happens between 0 to -5 C?
Cells and surrounding medium remain unfrozen and super-cooled
What happens between -5 to -15 C?
- Ice forms in external medium spontaneously or by controlled seeding
- Contents of cells remain unfrozen and super-cooled
What happens between -15 to -60 C?
Contents of cell freeze
What happens during Extracellular Ice Formation?
- Ice crystals form in EC space
- Cell membranes is permeable to liquid water but not ice
- Water expands as it freezes, EC ice crystals physically compresses cells
Why can Extracellular Ice cause mechanical damage to cell membrane?
Because the ice crystals are sharp
What happens during Solution Effects?
- Ice Crystals grow in freezing EC water
- Electrolytes and other solutes are excluded, causes them to become concentrated in reaming liquid water
During Solution Effects, Extracellular Fluid becomes HYPOtonic to cell.
T/F
False, it becomes HYPERtonic
What is “Osmolality?”
Concentration of particles dissolved in a fluid
What happens during Dehydration?
- Water migrates out of cell due to EX ice formation coupled with increasing solute concentration in liquid water
What is the fate of the cell during Dehydration?
What is the fate of the cell during Cytolysis?
- Cells shrinks from efflux of water
- Cell ruptures from influx of water
What happens during Intracellular Ice Formation?
- Intracellular ice is always fatal to cell, because organisms and tissues can tolerate some EC ice