Complete Blood Count (CBC) with Automated Differential, Blood - Saskatoon

Overview

Alias

• CBC

Specimen Information

Specimen types accepted

• Whole blood

Specimen collection container

• Preferred collection container: Lavender (4 mL K2 EDTA)
• Alternative collection container: Lavender (3 mL K2 EDTA)

Required volume

• Optimal volume: 4 mL
• Minimum volume: 1 mL

(Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection.) 

• Pediatric volume: 0.5 mL
• Capillary volume: 0.5 mL (minimum of 250 μL)

Transport and stability

•  CBC with automated differential, less than 6 hours
• CBC only less than 24 hours
• CBC with manual differential, less than 24 hours ensuring the manual slide is made within 6 hours

Rejection criteria

•  Clotted specimen
• Contaminated Specimen (drawn above an IV site)
• Specimen greater than 48 hours old
• Pathology and Laboratory Medicine Acceptance and Rejection Criteria

Performance

Days/times performed

Availability​

• 24 hours a day 7 days a week at RUH, SCH, SPH
• Stat CBCs available 

Maximum laboratory time

• ​Stat and Urgent CBCs are available within one hour of receipt in the lab at SPH, RUH and SCH
• In hospital within 2 hours
• Community Urgents within 4 hours
• Community routines within 24 hours
• Critical values will be phoned to the most responsible physician

 

 

Specimen retention time

• Specimens are stored in the lab for 72 hours

Other information

​Additional comments

• If platelet clumping occurs repeatedly it is recommended to repeat the collection with the addition of a Na Citrate (blue top) tube

​Reflex testing

• ​If abnormal results or flags on the CBC results from the analyzer are detected a peripheral smear will be made and a manual differential will be performed following lab protocol

Last Updated: November 4, 2026