diff --git a/db/migrate/20240708081135_add_insert_size_to_aliquots.rb b/db/migrate/20240708081135_add_insert_size_to_aliquots.rb
new file mode 100644
index 00000000..990197cf
--- /dev/null
+++ b/db/migrate/20240708081135_add_insert_size_to_aliquots.rb
@@ -0,0 +1,9 @@
+class AddInsertSizeToAliquots < ActiveRecord::Migration[7.0]
+  def up
+    add_column :aliquot, :insert_size, :integer, comment: 'The size of the insert in base pairs'
+  end
+
+  def down
+    remove_column :aliquot, :insert_size, :integer
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 6514896a..ee5ee844 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2024_06_14_135209) do
+ActiveRecord::Schema[7.0].define(version: 2024_07_08_081135) do
   create_table "aliquot", charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
     t.string "id_lims", null: false, comment: "The LIMS system that the aliquot was created in"
     t.string "lims_uuid", null: false, comment: "The UUID of the aliquot in the LIMS system"
@@ -25,6 +25,7 @@
     t.datetime "last_updated", null: false, comment: "The date and time that the aliquot was last updated"
     t.datetime "recorded_at", null: false, comment: "The date and time that the aliquot was recorded"
     t.datetime "created_at", null: false, comment: "The date and time that this record was created"
+    t.integer "insert_size", comment: "The size of the insert in base pairs"
   end
 
   create_table "bmap_flowcell", primary_key: "id_bmap_flowcell_tmp", id: :integer, charset: "utf8mb3", collation: "utf8mb3_unicode_ci", force: :cascade do |t|
diff --git a/spec/models/aliquots_spec.rb b/spec/models/aliquot_spec.rb
similarity index 93%
rename from spec/models/aliquots_spec.rb
rename to spec/models/aliquot_spec.rb
index 19ff5b2c..297f44d2 100644
--- a/spec/models/aliquots_spec.rb
+++ b/spec/models/aliquot_spec.rb
@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 describe Aliquot do
-  context 'aliquots' do
+  context 'aliquot' do
     let(:example_lims) { 'example' }
 
     let(:json) do
@@ -11,6 +11,7 @@
         'aliquot_type' => 'DNA',
         'volume' => 5.43,
         'concentration' => 2.34,
+        'insert_size' => 100,
         'lims_uuid' => '000000-0000-0000-0000-0000000002',
         'source_type' => 'library',
         'source_barcode' => 'PR-rna-00000001_H12',