Oct 22, 2021

Public workspaceAdult mouse kidney dissociation (on ice) V.9

  • Andrew Potter1
  • 1Cincinnati Children's Hospital Medical Center
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Protocol CitationAndrew Potter 2021. Adult mouse kidney dissociation (on ice). protocols.io https://dx.doi.org/10.17504/protocols.io.bzd9p296Version created by Andrew Potter
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License,  which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it’s working
Created: October 22, 2021
Last Modified: October 22, 2021
Protocol Integer ID: 54433
Keywords: kidney, dissociation, single cell
Abstract
Protocol for adult (8-10 week) mouse kidney dissociation performed on ice to reduce artifact gene expression. The protocol is based on our protocol published in Development for P1 mouse kidney, however this protocol includes two layers to provide additional enzymatic digestion. Cell viability is ~80% with major kidney cell types represented.
Guidelines

Bacillus Licheniformis Enzyme Mix (2 x 1 mL per 25 mg tissue):
100 µL b. lich 100 mg/mL (10 mg/mL final) (Sigma, P5380)
5 µL 1 M CaCl2 (5 mM)
5 µL DNAse (125 U) (StemCell, #07469)
890 µL DPBS (no Ca, Mg) ThermoFisher (cat. #14190)
Preparing enzymes:
The enzymes are made up in DPBS (#14190). They are aliquoted and stored at -80 ºC. FBS (for making the FBS/PBS) is heat-inactivated and sterile-filtered.

Required reagents: 
Red Blood Cell Lysis Buffer - Sigma (R7757)
Required Equipment & Consumables:
Thermomixer
Centrifuges for 1.5 mL and 15 mL conicals (MLS) Pipettes and pipet tips (MLS) 15 ml Conicals (MLS)
1.5 mL tubes (MLS) 30 µM filter (MLS) Petri dishes (MLS) Razor blades (MLS) Ice bucket w/ice (MLS) Hemocytometers - InCyto Neubauer Improved (DHC-NO1-5)
The protocol workflow is as follows:  A. Isolate Kidney
B. First layer C. Second layer D. Preparing cells for single cell analysis
Materials
MATERIALS
ReagentDPBS (no Ca, no Mg)ThermofisherCatalog #14190144
ReagentRBC Lysis Buffer SigmaCatalog #R7757

Before start
-Prepare enzyme mixes and leave on ice. 
-Cool centrifuges to 4 °C.
-Isolate and transport tissue in ice-cold DPBS. 
Isolate kidney
Isolate kidney
Perfuse kidneys to remove RBC. Extract and isolate kidneys in ice-cold PBS. Leave kidneys in ice-cold PBS until ready to dissociate (Up to 1 hr).


Coarsely mince tissue in PBS.

Duration00:02:00 mince on ice
Layer 1
Layer 1
Weigh out 25 mg coarsely minced tissue for each set of kidneys (remove PBS before weighing).

Amount25 mg minced kidney tissue
Continue mincing kidneys on top of petri dish, on ice, using razor blade in small vol. (~50 µL) PBS. (1-2 min) until fine paste.

Amount50 µL PBS

Prepare a separate 1 mL aliquot of B. Lich enzyme mix for each set of adult kidneys (prepare on ice). Use p200 w/cut tip to transfer minced kidney tissue from petri dish to tube of enzyme mix.

Amount1 mL B. Lich enzyme mix

Incubate digest mix for 10 min on ice with trituration and shaking. Triturate 15 strokes using 1 mL pipet set to 600 µL every 2 min; shake vigorously every min.
Duration00:01:00 shake vigorously
Duration00:02:00 triturate 15X
Duration00:10:00 incubate on ice
13m
After 10 min, let tissue chunks settle on ice for 1 min. Save supernatant (700 µL, 70%) and apply to 30 µM filter on 15 mL conical. Rinse filter w/5 mL 10% FBS/PBS. Leave filter on 15 mL conical for the next layer.

Duration00:01:00 let tissue chunks settle
Amount700 µL save supernatant
Amount5 mL rinse filter with 5 mL 10% FBS/PBS

1m
Layer 2
Layer 2
Add additional 700 µL B. Lich enzyme mix to residual tissue chunks. Continue incubating on ice 15-20 min with shaking and trituration, until tubules and glomeruli are fully broken up.

Amount700 µL B. lich enzyme mix

Duration00:01:00 shake vigorously
Duration00:02:00 triturate 15X
Duration00:20:00 incubate on ice
23m
Once digestion is adequate (tubules / glomeruli are broken up), triturate and add entire digest mix to same 30 µM filter as used in previous step on 15 mL conical.
Spin 15 mL conical with combined flow-through from layer 1 and layer 2 (isolated cells) 300 g for 5 min at 4 °C.

Duration00:05:00 300 g at 4 °C

5m
Prepare cells for 10X Chromium / scRNA-Seq
Prepare cells for 10X Chromium / scRNA-Seq
Discard supernatant. If necessary, perform RBC removal according to manufacturers instructions.

Re-suspend cells in 10 mL 10% FBS/PBS. Spin 300 g for 5 min at 4 °C. 

Amount10 mL 10% FBS/PBS
Duration00:05:00 spin 300 g
Discard supernatant. Re-suspend cells in 500 µL 10% FBS/PBS (or other compatible buffer). Analyze cell viability and concentration using trypan blue dye exclusion with a hemocytometer. Adjust cell concentration to 700-1,200 cells/µL for 10X single cell 3'v3.1.

Amount500 µL 10% FBS/PBS