[kingbedjed]

The request

Slack user U0APRMP9RH8 asked for this plate in #labware-requests on 2026-10-30 (permalink):

corning 96-well black spheroid plate cat no. 4520

Closes #38

Decisions needed

• Well bottom radius left out. Corning's Product Description gives "Well bottom radius 0.100 in" (2.54 mm). A sphere of that radius cannot span the 6.35 mm bottom diameter on the dimension sheet; that would need at least 3.175 mm. So the 2.54 mm is either a corner radius or describes a smaller pocket than the published bottom, and no Corning document says which. The file has bottom_shape: u and no bottom_radius, so readers draw a hemisphere. Keep it that way, or ask Corning?
• Footprint length. The sheet prints 127.6 mm for its spheroid rows, while the 4520 Product Description gives 127.76 mm. The file carries 127.76 × 85.48, the same call as Corning_3830_384_well_plate.json. Change it if a plate in hand measures 127.6.
• Well depth. The sheet gives 12.36 mm. The Product Description gives 0.494 in (12.55 mm), which is outside its own ±0.010 in tolerance and is the same figure it prints for the 384-well 3830. The file follows the sheet.
• The vertical stack does not close. Depth 12.36 + floor height 2.03 = 14.39 mm, against a 14.2 mm plate height. Each value is recorded as printed.

What is included

file	plate	pitch	grid	A1 (left / top)	bottom
Corning_4520_96_well_plate.json	Corning 4520 96 well spheroid	9 mm	8 × 12	14.27 / 11.2 mm	clear polystyrene, 0.0875 mm, U (round), Ø6.35 mm (top Ø6.85 mm), 12.36 mm deep

Figures

rendered from the JSON on this branch	Corning's own
	Product Description 4520, Rev 4, Feb 9 2026, page 1
	Family photo from the 4520 catalogue page

The controlling document is the Microplate Dimensions 96/384/1536 sheet, row "96 well spheroid plate". It is linked here, not reproduced, because its footer reads "Corning Restricted". It is a table with no drawing, so the only pictures Corning publishes for this plate are the photo and the Product Description.

Sources used

• Corning Microplate Dimensions 96/384/1536 sheet (controlling; drawing_reference), row "96 well spheroid plate", which names 4515 and 4520. Corning publishes no per-catalogue drawing for assay plates: drawings/DWG4520.PDF, 4520.pdf and LSR4520.pdf all return 404.
• Corning Product Description 4520, Rev 4, Feb 9 2026 (cross-check). It is imperial at ±0.010 in. 4515's Rev 3 carries identical dimensions.
• The catalogue page (web_reference). It says 4520 is the bulk-packed 10/bag version, and gives 300 µL well volume, a 75–300 µL working volume, sterile, with lid.

Judgement calls

• diameter 6.35 mm is the sheet's bottom figure and diameter_top 6.85 mm the opening (the Product Description gives 0.270 in = 6.858 mm at the top).
• A1 is at 14.27 mm from the left ("A1 Column Offset") and 11.2 mm from the top ("A1 Row Offset"), as printed. That is 0.11 mm left of the centred 14.38 mm. The sheet prints 14.27 only for the spheroid row; Corning's other 96-well rows print 14.3.
• bottom_elevation 1.86 mm is the sheet's "Distance to bottom of plate", and the Product Description's 0.073 in (1.854 mm) agrees. floor_height 2.03 mm is the sheet's "Well Bottom Elevation" column. On the sheet's other rows that column is the floor's upper surface: for "96 well flat bottom", 2.26 + 1.27 = 3.53 against the printed 3.55. For this row 1.86 + 0.0875 = 1.95 misses 2.03 by 0.08 mm, which is inside the schema's 0.1 mm tolerance.
• The 0.0875 mm bottom thickness is printed on the sheet only. It is unusually thin and has not been checked against a plate.
• height_with_lid 16.51 mm is the Product Description's 0.650 in. skirt_height 6.096 mm is the sheet's flange height. The skirt outline is not published, so the standard outline is assumed.
• 4515 is the same mould (same sheet row, same Product Description dimensions). It is named in notes and not registered separately.

Testing

• pytest -q: 184 passed.
• lint (CI pins: ruff 0.15.22, ty 0.0.74): ruff check ., ruff format --check . and ty check all pass.
• check_labware.py:

Corning_4520_96_well_plate.json
  name            'Corning 4520 96 well spheroid'   part '4520'
  footprint       127.760 mm x 85.480 mm x 14.200 mm
  grid            8 rows x 12 cols, pitch 9.000 mm
  well            circle, 6.850 mm at the top, 6.350 mm at the bottom, 12.360 mm deep, u bottom
  A1 centre       14.270 mm from left, 11.200 mm from top
  far margins     14.490 mm right, 11.280 mm bottom
  centred A1      14.380 mm / 11.240 mm  (delta -0.110 mm / -0.040 mm)
  ok

🤖 Generated with Claude Code

Opened by the add-labware skill of ramona-claude 0.16.0 (ramona-llm c377eb0, prompt bc769991).