Beta-hydroxybutyrate ketone concentrations via ketometer and colorimetric assay in Steller sea lion whole blood and plasma

We evaluated the Precision Xtra™ ketometer during a larger study categorizing free-ranging Steller sea lion (Eumetopias jubatus; SSL) pup fasting status, necessitating identification of plasma β-hydroxybutyrate concentrations ([β-HBA]) around a < and ≥0.3 mmol/L threshold. Whole blood samples mixed with sodium heparin (NaHep) or ethylenediaminetetraacetic acid liquid anticoagulants were tested <10 minutes after collection (n=14; triplicate technical replicates). Plasma (stored at -80°C, NaHep, Thaw1) measured via our laboratory’s Reference Assay (Sigma Aldrich, St. Louis, MO, Kit #MAK041) served as the standard [β-HBA] for ketometer comparisons. Our observed β-HBA range (0.0–1.6 mmol/L), consistent with published [β-HBA] of free-ranging Otariid pups, represented the lower 20% of the ketometer’s range (0.0–8.0 mmol/L). The maximal coefficient of variation (%CV) of ketometer technical replicates was 9.1% (NaHep, whole blood). The majority of ketometer technical replicate sets (84%, ..., Steller sea lion pups were captured live at the Chiswell Island rookery in southcentral Alaska in June 2016. These pups were handled as part of collaborative ongoing research by the Alaska SeaLife Center and the Alaska Department of Fish and Game under Marine Mammal Protection Act permit numbers 18537-00 and 18438-00. Blood samples were drawn from anesthetized pups at the vein of the caudal gluteal plexus directly into blood collection tubes treated with anticoagulants (ethylenediaminetetraacetic acid or sodium heparin). 
The calibration of the ketometer was tested at the beginning of each day of use using low (0.4–0.8 mmol/L) and high (3.1–5.1 mmol/L) control solutions provided by the manufacturer. Within ten minutes of collecting a blood sample, the whole blood [β–HBA] was measured by the Precision Xtra™ ketometer in triplicate technical replicates following manufacturer instructions for both types of anticoagulant blood collection tubes.
Samples in blood collection tubes were kept ch..., , # Beta-hydroxybutyrate ketone concentrations via ketometer and colorimetric assay in Steller sea lion whole blood and plasma

[https://doi.org/10.5061/dryad.qfttdz0ps](https://doi.org/10.5061/dryad.qfttdz0ps)

The data consist of five separate measurements of beta hydroxybutyrate (mmol/L) on blood or plasma samples collected from each of 14 Steller sea lion pups.  The five measurements vary by method, blood compartment, anticoagulant, and/or storage history.
 
**The data are organized into 13 columns:**
 
SSL Pup                      range 1–14; corresponds to ID in Table 3 and Figure 1 in linked publication
 
PupID                         unique identifier for each Steller sea lion pup
 
Method                      technique used to obtain B-HBA concentration:  A=Assay; K=Ketometer
 
Matrix                         blood compartment tested:  WB=whole blood; PL= plasma
 
Anticoagulant           chemical that blood collection tube was treated with to prevent
coagulation: NaHep=sodium hep...