Standardization of procedures and reporting in cryopreservation - - PowerPoint PPT Presentation

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Standardization of procedures and reporting in cryopreservation - - PowerPoint PPT Presentation

Dec 24, 2022 141 likes •399 views

Standardization of procedures and reporting in cryopreservation kos Horvth DEPARTMENT OF AQUACULTURE Overview Why are we cryopreserving sperm? Identification of the problem Possible solutions to the problem Does

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DEPARTMENT OF AQUACULTURE

Standardization of procedures and reporting in cryopreservation

Ákos Horváth

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DEPARTMENT OF AQUACULTURE

Overview

  • Why are we cryopreserving sperm?
  • Identification of the problem
  • Possible solutions to the problem
  • Does standardization limit scientific freedom?
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DEPARTMENT OF AQUACULTURE

Why do we develop methods?

  • To be used in aquaculture practice

– to assist reproduction in aquaculture – to be applied to selective breeding programs – to be applied to conservation of genetic resources

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DEPARTMENT OF AQUACULTURE

Use of cryopreservation methods in aquaculture

  • Very limited
  • Applied on an individual basis
  • Reasons:

– sperm is seldom a limiting factor – limited use of selective breeding – lack of standardization

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DEPARTMENT OF AQUACULTURE

Standardization problems

Method

development Publication Replication problems Rejection by industry

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DEPARTMENT OF AQUACULTURE

Standardization problems

  • Definitions
  • Methods
  • Publications
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DEPARTMENT OF AQUACULTURE

Typical problems

  • Extenders
  • Dilution ratios
  • Cryoprotectant

concentrations

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DEPARTMENT OF AQUACULTURE

Problems with definitions

  • Extenders

– What is an extender?

  • Cryoprotectant concentrations

– In percentages or molars? – Relative to the final dilution or to the extender?

  • Dilution ratios

– Are they meaningful? – Sperm as a substance or sperm as a concentration of cells

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DEPARTMENT OF AQUACULTURE

Problems with methods

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DEPARTMENT OF AQUACULTURE

Problems with methods

  • Sperm concentration determination

– Which method to use?

  • Sperm cryopreservation methods

– Equilibration – Handling of straws – Polystyrene box or controlled-rate freezer

  • Calculation of fertilization and hatch rates
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DEPARTMENT OF AQUACULTURE

Problems with methods

  • Osmolality measurements

– Wapor pressure or freezing point- depression osmometer?

  • CASA measurements
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DEPARTMENT OF AQUACULTURE

Problems with publication

  • Lack of guidelines or good laboratory practices
  • Lack of standard procedures
  • Lack of definitions
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DEPARTMENT OF AQUACULTURE

Problems with the industry

  • Standards exist but are they applicable to aquaculture?
  • Lack of branding
  • Lack of quality control
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DEPARTMENT OF AQUACULTURE

Is there really a problem with the industry?

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DEPARTMENT OF AQUACULTURE

Standardization

  • Standardization of definitions
  • Standardization of protocols
  • Standardization of reporting
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DEPARTMENT OF AQUACULTURE

Standardization of definitions

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DEPARTMENT OF AQUACULTURE

Standardization of definitions

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DEPARTMENT OF AQUACULTURE

Standardization of protocols

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DEPARTMENT OF AQUACULTURE

Standardization of protocols

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DEPARTMENT OF AQUACULTURE

Standardization of reporting

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DEPARTMENT OF AQUACULTURE Example: standardization for high-throughput cryopreservation of hybrid catfish (E Hu, High-throughput sperm cryopreservation of aquatic species, PhD Dissertation, Louisiana State University, 2012)

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DEPARTMENT OF AQUACULTURE Example: standardization for high-throughput cryopreservation of hybrid catfish (E Hu, High-throughput sperm cryopreservation of aquatic species, PhD Dissertation, Louisiana State University, 2012)

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DEPARTMENT OF AQUACULTURE Example: standardization for high-throughput cryopreservation of hybrid catfish (E Hu, High-throughput sperm cryopreservation of aquatic species, PhD Dissertation, Louisiana State University, 2012)

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DEPARTMENT OF AQUACULTURE

Acceptance by scientists

  • Does it limit scientific freedom?
  • Do I have to follow the published protocols?
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DEPARTMENT OF AQUACULTURE

Acceptance by scientists

  • Scientific freedom sloppy reporting
  • No application without standardization
  • Standard terms can be used as a reference and a starting point