See JAX Pipeline on the IMPC website for order of tasks for all mice tested

Project protocol: Heart weight

• Introduction
• Study design
• Workflow
• Equipment, software and supplies
• Reagents and solutions
• Procedure
• Measurements
• Experimental and technical parameters

Introduction

Using heart weight and body weight to evaluate cardiac size.

Study design

Paradigm: Baseline study

Panel: Collaborative Cross

Number of strains: 18

Sex: Both

Age: 17-19 wks

Sample size: Six mice per sex from at least two litters

Number of cohorts: 1

Workflow

Step	Description	Equipment	Data collected
1	Mice are euthanized	-	-
2	Weigh each mouse	Balance	Body weight
3	Dissect and weigh heart	Balance	Heart weight

Equipment, software and supplies

• Balance: Ohaus AV212C [See Experimental and technical parameters]
• Fine forceps
• Surgical scissors
• Fine surgical scissors
• Kim wipes or surgical compress
• Corkplate or wax board
• Pins

Reagents and solutions

• 70% ethanol

 

Procedure

1. Mice are euthanized via cervical dislocation.
2. Body weight is recorded.
3. Each mouse is placed on its back and pinned onto the board (inner side of front and hind paws).
4. Each mouse is doused with 70% ethanol to control hair and dander.
5. The heart is dissected (dissect aortic root immediately above the aortic valves and the superior vena cava above the atria).
6. Mediastinal fat pads are carefully removed with forceps.
7. Blood is removed from the heart with Kim wipes or surgical compress until the heart is totally dry.
8. The heart is weighed.

 

Formulas and derivations: Local data processing is implemented to calculate derived measures from these data, and a table of the derived measures and raw data are reported per mouse in JaxLIMS.

 

Measurements

LIMS field name	MPD variable name	Description	Units	Series	Primary measurement	Series order	MPD computed	Calculation	Method	Data type
Body weight	bw	body weight	g						body weight	Float
Heart weight	heart_wt	heart weight, weight	mg	Yes	heart_wt	1			organ weight	Float
HW/BW	heart_wt_adj	heart weight, normalized to body weight	mg	Yes	heart_wt	2			organ weight	Float

Experimental and technical parameters

Equipment name	Balance
Equipment manufacturer	Ohaus
Equipment model	AV212C