Fertilization and early embryology

Direct assessment of cryopreservation of human spermatozoa using a cryomicroscope and computer-aided sperm analysis

S. N. Mohammad, C. L. R. Barratt, I. D. Cooke, H. D. M. Moore

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Use of a cryostage has enabled direct observation of human spermatozoa as they are cryopreserved and thawed. Crystallization and recrystallization events are readily observed. In combination with computer-aided semen analysis (CASA) equipment it was possible to determine the consequence of altering the cooling, freezing and thawing rates of a temperature-rate profile on sperm motility. Increasing the cooling rate to 50 degrees C/min resulted in significantly lower pre-freeze to post-thaw ratios for average path velocity (VAP, 13%), mean straight line velocity (VSL, 35%), mean linearity (LIN, 28%) and straightness (STR, 24%), while the ratio of the number of cells crossing the field of view (NCF) significantly increased (30%) compared to a standard freeze-thaw temperature rate profile. The NCF pre-freeze to post-thaw ratio was associated with the percentage of cell recovery after cryopreservation. Faster thaw rates resulted in better survival of the cells, perhaps due to the shorter time during which recrystallization occurred. The NCF ratios were significantly higher (33 and 30% for thaw rates of 50 and 100 degrees C/min respectively) than for the standard profile samples. Previous studies on cell survival have shown a link between the cooling and thaw rates. The cryostage should prove invaluable in future studies to identify the causes of cryodamage to spermatozoa. When used in combination with CASA, changes to sperm function during cryopreservation can be accurately measured.

Original languageEnglish
Pages (from-to)2687-92
Number of pages6
JournalHuman Reproduction
Volume11
Issue number12
DOIs
Publication statusPublished - Dec 1996

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Embryology
Cryopreservation
Fertilization
Spermatozoa
Semen Analysis
Cell Survival
Temperature
Sperm Motility
Crystallization
Freezing
Cell Count
Observation
Equipment and Supplies

Keywords

  • Computers
  • Cryopreservation/methods
  • Crystallization
  • Hot Temperature
  • Humans
  • Kinetics
  • Male
  • Microscopy/methods
  • Spermatozoa/physiology

Cite this

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title = "Fertilization and early embryology: Direct assessment of cryopreservation of human spermatozoa using a cryomicroscope and computer-aided sperm analysis",
abstract = "Use of a cryostage has enabled direct observation of human spermatozoa as they are cryopreserved and thawed. Crystallization and recrystallization events are readily observed. In combination with computer-aided semen analysis (CASA) equipment it was possible to determine the consequence of altering the cooling, freezing and thawing rates of a temperature-rate profile on sperm motility. Increasing the cooling rate to 50 degrees C/min resulted in significantly lower pre-freeze to post-thaw ratios for average path velocity (VAP, 13{\%}), mean straight line velocity (VSL, 35{\%}), mean linearity (LIN, 28{\%}) and straightness (STR, 24{\%}), while the ratio of the number of cells crossing the field of view (NCF) significantly increased (30{\%}) compared to a standard freeze-thaw temperature rate profile. The NCF pre-freeze to post-thaw ratio was associated with the percentage of cell recovery after cryopreservation. Faster thaw rates resulted in better survival of the cells, perhaps due to the shorter time during which recrystallization occurred. The NCF ratios were significantly higher (33 and 30{\%} for thaw rates of 50 and 100 degrees C/min respectively) than for the standard profile samples. Previous studies on cell survival have shown a link between the cooling and thaw rates. The cryostage should prove invaluable in future studies to identify the causes of cryodamage to spermatozoa. When used in combination with CASA, changes to sperm function during cryopreservation can be accurately measured.",
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Fertilization and early embryology : Direct assessment of cryopreservation of human spermatozoa using a cryomicroscope and computer-aided sperm analysis. / Mohammad, S. N.; Barratt, C. L. R.; Cooke, I. D.; Moore, H. D. M.

In: Human Reproduction, Vol. 11, No. 12, 12.1996, p. 2687-92.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fertilization and early embryology

T2 - Direct assessment of cryopreservation of human spermatozoa using a cryomicroscope and computer-aided sperm analysis

AU - Mohammad, S. N.

AU - Barratt, C. L. R.

AU - Cooke, I. D.

AU - Moore, H. D. M.

PY - 1996/12

Y1 - 1996/12

N2 - Use of a cryostage has enabled direct observation of human spermatozoa as they are cryopreserved and thawed. Crystallization and recrystallization events are readily observed. In combination with computer-aided semen analysis (CASA) equipment it was possible to determine the consequence of altering the cooling, freezing and thawing rates of a temperature-rate profile on sperm motility. Increasing the cooling rate to 50 degrees C/min resulted in significantly lower pre-freeze to post-thaw ratios for average path velocity (VAP, 13%), mean straight line velocity (VSL, 35%), mean linearity (LIN, 28%) and straightness (STR, 24%), while the ratio of the number of cells crossing the field of view (NCF) significantly increased (30%) compared to a standard freeze-thaw temperature rate profile. The NCF pre-freeze to post-thaw ratio was associated with the percentage of cell recovery after cryopreservation. Faster thaw rates resulted in better survival of the cells, perhaps due to the shorter time during which recrystallization occurred. The NCF ratios were significantly higher (33 and 30% for thaw rates of 50 and 100 degrees C/min respectively) than for the standard profile samples. Previous studies on cell survival have shown a link between the cooling and thaw rates. The cryostage should prove invaluable in future studies to identify the causes of cryodamage to spermatozoa. When used in combination with CASA, changes to sperm function during cryopreservation can be accurately measured.

AB - Use of a cryostage has enabled direct observation of human spermatozoa as they are cryopreserved and thawed. Crystallization and recrystallization events are readily observed. In combination with computer-aided semen analysis (CASA) equipment it was possible to determine the consequence of altering the cooling, freezing and thawing rates of a temperature-rate profile on sperm motility. Increasing the cooling rate to 50 degrees C/min resulted in significantly lower pre-freeze to post-thaw ratios for average path velocity (VAP, 13%), mean straight line velocity (VSL, 35%), mean linearity (LIN, 28%) and straightness (STR, 24%), while the ratio of the number of cells crossing the field of view (NCF) significantly increased (30%) compared to a standard freeze-thaw temperature rate profile. The NCF pre-freeze to post-thaw ratio was associated with the percentage of cell recovery after cryopreservation. Faster thaw rates resulted in better survival of the cells, perhaps due to the shorter time during which recrystallization occurred. The NCF ratios were significantly higher (33 and 30% for thaw rates of 50 and 100 degrees C/min respectively) than for the standard profile samples. Previous studies on cell survival have shown a link between the cooling and thaw rates. The cryostage should prove invaluable in future studies to identify the causes of cryodamage to spermatozoa. When used in combination with CASA, changes to sperm function during cryopreservation can be accurately measured.

KW - Computers

KW - Cryopreservation/methods

KW - Crystallization

KW - Hot Temperature

KW - Humans

KW - Kinetics

KW - Male

KW - Microscopy/methods

KW - Spermatozoa/physiology

U2 - 10.1093/oxfordjournals.humrep.a019192

DO - 10.1093/oxfordjournals.humrep.a019192

M3 - Article

VL - 11

SP - 2687

EP - 2692

JO - Human Reproduction

JF - Human Reproduction

SN - 0268-1161

IS - 12

ER -