Post Thaw Motility Loss
Compare observed motility before freezing and after thawing; motility is not a definitive viability test.
Description
Motility before and after thawing is commonly summarized as a proportion of counted organisms.
Motility before and after thawing is commonly summarized as a proportion of counted organisms. A difference in percentages describes the change on a percentage-point scale.
The tool returns preFreezeMotilityPercent (pre freeze motility percent); postThawMotilityPercent (post thaw motility percent); motilityChangePoints (motility change points). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Post Thaw Motility Loss
Use Post Thaw Motility Loss when you already have preFreezeMotile, preFreezeTotal, postThawMotile, postThawTotal and want preFreezeMotilityPercent, postThawMotilityPercent, motilityChangePoints. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Post Thaw Motility Loss and understand its results
- Enter preFreezeMotile, preFreezeTotal, postThawMotile, postThawTotal using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read preFreezeMotilityPercent, postThawMotilityPercent, motilityChangePoints. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| preFreezeMotile | Pre freeze motile | integer | Required |
| preFreezeTotal | Pre freeze total | integer | Required |
| postThawMotile | Post thaw motile | integer | Required |
| postThawTotal | Post thaw total | integer | Required |
Validate motile counts against positive total counts at each measurement, then subtract the pre-thaw percentage from the post-thaw percentage.
motility% = 100 × motile/total; change = postThaw% − preThaw% The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"preFreezeMotile": 80,
"preFreezeTotal": 100,
"postThawMotile": 60,
"postThawTotal": 100
},
"output": {
"preFreezeMotilityPercent": 80,
"postThawMotilityPercent": 60,
"motilityChangePoints": -20
}
}Limitations and assumptions
A decline gives a negative change, not a positive relative loss percentage. Motility alone is not a viability or infectivity assay.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
ELISA Cutoff Index: Calculate a blank-corrected ELISA cutoff index using the supplied assay cutoff. Snail Shedding Output: Normalize observed cercarial output to total snail-hours of observation.
Methodological background: DPDx: diagnostic procedures.1
References
-
DPDx: diagnostic procedures — Centers for Disease Control and Prevention
Similar or alternative tools
- ELISA Cutoff Index
Calculate a blank-corrected ELISA cutoff index using the supplied assay cutoff.
- Snail Shedding Output
Normalize observed cercarial output to total snail-hours of observation.