IVF Culture Media Flashcards
laboratory procedures
Maternal meiotic error is the major contributor to embryonic aneuploidy
true
Regarding Polar Body biopsy What is True:
a. It is possible to determine whether the chromosomes segregated correctly during meiosis
b. Both polar bodies need to be analyzed
c. It is cheaper and quicker than embryonic biopsy
d. Polar body biopsy has been advocated as a less invasive procedure than embryo biopsy
e. No loss of tissue given the polar bodies are lost to the embryo
a, b, d, e
What is true:
- Cleavage stage biopsy may cause some harm
- Cleavage stage biopsy does not cause any harm
- Trophectoderm biopsy may cause harm
- Trophectoderm biopsy does not cause harm
- Polar body biopsy may cause harm
- Polar body biopsy does not cause harm
- Blastocyst biopsy appears to provide the best estimate of ploidy
- The predictive power of polar body biopsy is the same for cleavage and blastocyst transfer
- The predictive power of polar body biopsy is different for cleavage and blastocyst transfer
1, 3, 6, 7 and 9
Potential ingredients for an embryo culture media?
Water
Inorganic ions
Energy substrates
Amino Acids
Vitamins
Fatty acids or premetabolites
Nucleic acids premetabolites
Chelators
Antioxidants
Proteins or macromolecules
Polypeptide growth factors or hormones
Buffering systems
Antibiotics
A high Na+/K+ ratio may result in:
- Increased development
- No discernible effect
- Decreased development
c.
Which may be correct when discussing the phenomenon of the 2-cell block 2CB?
a. The 2CB may be caused by high glucose concentrations
b. The 2CB may be caused by high pyruvate concentrations
c. The 2CB may be caused by high phosphate concentrations
d. Removal of glucose and pyruvate will alleviate the 2CB
e. Removal of glucose and phosphate will alleviate the 2CB
f. Addition of amino acids will alleviate the 2CB
a, c, e, f
Most culture media contain phosphate ions in the concentration of:
- Between 0.15 and 0.25 m. Eq/L
- Between 0.20 and 0.25 m.Eq/L
- Between 0.25 and 0.35 m.Eq/L
- Between 0.25 and 0.45 m.Eq/L
- Between 0.35 and 0.45 m.Eq/L
3.
A high Mg2+/Ca2+ Ratio is used in IVF culture media because:
1-A high Ca2+/Mg2+ ratio may lead to an excessive uptake of Ca2+
2-Most of the rise in Ca2+ came from intracellular stores.
3-A high Ca2+ results in metabolic perturbations and decreased development
4-Embryos de-compact in Ca2+/Mg2+ free media (biopsy media)
5-Fertilization media has a low Mg2+ since a Ca2+ spike is part of the acrosome reaction
1-
-Calcium acts as a second messenger in various cellular processes, including fertilization, cell division, and gene expression. During early preimplantation development
-Magnesium is a cofactor for many enzymes involved in energy production, DNA synthesis, and other cellular functions.
The pre-compaction stage embryo prefers:
- pyruvate to glucose
- glucose to pyruvate
- neither pyruvate or glucose
- both pyruvate or glucose
1
Embryo prefer pyruvate than glucose in early stages
prior compaction (d0-d3 cleavage stage) embryo development
The post compaction stage embryo (morula and blastocyst) prefers:
- pyruvate to glucose
- glucose to pyruvate
- neither pyruvate or glucose
- both pyruvate or glucose
2.
cleavage stage ►pyruvate
morula-blastocyst►►Glucose
Which enzyme is inhibited by high ATP:ADP ratios?
a. hexokinases
b. Phosphoglucose isomerase
c. Phosphofructokinase (PFK)
d. aldolase
e. Pyruvate kinase
c.
Phosphofructokinase (PFK) Enzyme ¢ inhibited by high ATP:ADP ratios,
and vice versa
Phosphofructokinase (PFK) Enzyme ⇒»»stimulated by low ATP:ADP ratios,
Prior to Compaction: which is true?
a. glucose consumption is low
b. glucose consumption is high
c. some glucose consumption is required for intracellular purposes
d. pyruvate is the principle energy source
e. The TCA cycle remains the main source of energy
f. ATP levels are high
g. ADP levels are high
h. Oxygen consumption is high
i. Oxygen consumption is low
a, c, d, e, f, i
glucose consumption is low
some glucose consumption is required for intracellular purposes
pyruvate is the principle energy source
The TCA cycle remains the main source of energy
ATP levels are high
Oxygen consumption is low
Following Compaction:
- glucose consumption is low
- glucose consumption is high
- some glucose consumption is required for intracellular purposes
- pryuvate is the principle energy source
- The TCA cycle remains the main source of energy
- ATP levels are high
- ADP levels are high
- Oxygen consumption is high
- Oxygen consumption is low
2, 3, 5, 7, 8
glucose consumption is high
some glucose consumption is required for intracellular purposes
The TCA cycle remains the main source of energy
ADP levels are high
Oxygen consumption is high
Which is the most stable form of pyruvate
- pyruvate
- ethyl pyruvate
- methyl pyruvate
b
Glucose consumption by morula may be used to predict the better-quality embryo.
True
Which genders has the higher glucose consumption on day 4
- Male human embryos
- Female human embryos
- Neither, they both have the same consumption
2
Some recent studies suggest that there might be a difference in glucose consumption between male and female embryos on day4 -Studies have shown that female embryos may consume slightly more glucose than male embryos.
The Primary animal used for early attempts at embryo culture was the:
Rabbit
Early Attempts at Rabbit Embryo Culture by Hammonds was made in media containing:
Egg white
Egg yolk
Media developed by Whitten and later by Brinster & Biggers included the following components:
Bovien serum albumin
Glucose
Lactate
Antibiotics
Bicarbonate
The PH of early media was adjusted to……
7.4
Who Reported the first birth from the transfer of in vitro cultured mouse embryos?
??????
back to previous Cards
The Back to Nature Approach in the development of culture media sought to emulate the environment of:
The Fallopian Tube
Concept of changing substrates requirements of the embryo throughout development lead to the introduction of:
Sequential Media
preimplantation embryo developmental arrests in some strains of mouse embryos were overcome by:
Reduce glucose until the 8 cell stage
Modifying the lactate/pyruvate ratios
Including glutamate
Including EDTA
If media were to be developed to reflect the changing environment of the preimplantation embryo, then which of the following stages should be considered:
Follicular fluid
The ampulla
The ampulla-isthmic junction
The oviduct
The uterus
Which of the following areas may be considered to be the important challenges to be addressed in future media developments:
The roles of amino acids
The relevance to toxicity due to amino acid metabolism/breakdown
The role of growth factors
The importance of paracrine/autocrine embryo factors
The relevance of mouse based additives to human IVF culture media
The importance of sufficiently powered, randomized controlled studies
Focus on the long term health of offspring
Mineral Oil role in culture systems includes:
Protects the culture medium from evaporation
Protects the culture medium from contamination
Protects the culture medium from fluctuations in pH and Temperature
Protects the culture medium from fluctuations in osmotic pressure
Oil acts as Sink for VOCs
OIL acts as Barrier between CM and the ambient environment
Levels of Oxidative Stress and the Production of Reactive Oxygen Species (ROS) have been shown to
Impact negatively on embryo development
Endogenous Cellular Antioxidants can be
- Both enzymic and non-enzymic
- Only enzymic
- Only non-enzymic
1
Hypotaurine is an Example of Non-Enzymic Anti-Oxidant
true
Hypotaurine a sulfinic acid that is an intermediate in the biosynthesis of taurine. Like taurine,
it also acts as an endogenous neurotransmitter via action on the glycine receptors.
It is an osmolyte with antioxidant properties (antioxidant)
Examples of cNon-Enzymic Anti-Oxidant
- superoxide dismutase
- glutathione peroxidase
- gamma-glutamylcysteine synthetase
Which of the following are true?
a. there is an absence of understanding the complexity of the pro-oxidant-antioxidant equilibrium.
b. most IVF culture media contains antioxidants
c. taurine and ascorbic acid are common antioxidants in culture media
d. taurine, hypotaurine and ascorbic acid are common antioxidants in culture media
e. glucose can also be used as an antioxidant
f. ROS stress can be reduced by culturing in low oxygen concentrations
g. despite the risks of ROS stress many clinics still culture in a high oxygen atmosphere
a, b, c, f, and g
Rational behind Changing or Refresh Culture Media which may help to:
Remove ROS
Remove by-products of metabolism
refresh substrates
replace the media with new compositions appropriate to their stage of development
With respect to changing ( Refresh) the media, which of the main debates?
Supporting data is controversial
The main argument for refreshing media is to replace ammonia from protein breakdown
Refreshing media may remove positive embryo trophic factors
New media formulation suggest changing media may not be necessary
Buildup of waste products or embryo positive factors may depending on:
Time dependent
Drop volume dependent
Embryo density dependent (number of embryos per drop)
media dependent
embryo quality dependent
environment dependent
embryo stage dependent
Mixing good and poor-quality embryos in the same drop is NOT recommended, because it may diminish the quality of the good embryos
true
New Culture Systems such as microfluidic or vibrational systems may make excessive refreshment
TRUE
What arethe common reasons of result in Precipitation of calcium as CaCO3 and calcium phosphate in IVF culture media?
Precipitation of calcium in CM maybe due to:
Aged media, particularly if it has attained a very alkaline pH
Stored in too cold refrigerator
Interacellular Glutathione (GSH) protection roles.
Glutathione production is a critical event within oocyte before fertilization it’s protection roles involved:
1. Intracellular anti-oxidant against ROS
2. protects the cell membrane from peroxide damage
