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200-micron laser-drilled pore

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Macropore used on Molecular Reality's live stream
A dark oval opening seen through a microscope, with a red point of light near its center and small bright specks
The pore as pictured on the company's shelf of provisions, a dark opening about 200 micrometers across

The 200-micron laser-drilled pore is the hole through which Molecular Reality Corporation measures the current on its live molecular stream. It is about 200 micrometers (0.2 mm) across, was made by laser drilling, and is listed on the company's shelf of laboratory provisions as a "laser-drilled macropore".[1] That is more than 100,000 times the width of the narrowest point of a protein nanopore, and about the size of the apertures that Coulter counters use to count blood cells. A pore this wide can register cells and other particles several micrometers across. A single molecule passes through it unseen.[2]

The company's guide for visitors says that "the pores we stream today are larger than a nanometer" and that "All pore based sensing is one family, and we are walking it from the big end toward the small", a program it compresses into one line: "The road to the small end runs through the big end, and the big end loves ketchup."[3]

Description

The pore was entered in the stream's list of provisions on June 16, 2026. The entry gives its history in one sentence: "from Potomac, full description will require later data archeology, from around 2019 but showed Phmic[sic] behavior consistent with their size in last few weeks after wetting (Late May, Early Jun 2026)".[1][a] A photograph on the shelf, taken through a microscope, shows a dark oval opening with a single red point of light near its middle and a scatter of bright specks.[1]

On the stream, an EDR4 amplifier reads the current through the pore 200,000 times a second.[3] It sits in a flow cell of acetal and PTFE that the company calls a "d2600 style cell".[1] The archive's first listed recording that names the pore is an air test of about two minutes made on the afternoon of June 22, 2026, in a cell entered as "08-delrin-ptfe-demonpore2600-style".[4]

Scale

Two hundred micrometers is 200,000 nanometers, about two and a half times the thickness of a human hair, which the company's guide puts at "about eighty thousand nanometers".[3] The narrowest part of alpha-hemolysin, the protein pore used in the first experiments that detected single DNA strands, is about 1.4 nm wide.[5] Compared with a model solid-state pore 5 nm wide, the laser-drilled hole has 1.6 billion times the cross-section.[2]

For apertures of this size the closer relative is the Coulter counter. Wallace H. Coulter patented the method in 1953 to count blood cells by the pulses they make as they pass a small aperture, and hematology analyzers still use it.[6] The company describes itself in the same terms: "We are a small branch on a seventy year old tree, and the tree is wonderful."[3]

Physics

See also: Pore conductance, Access resistance, and Coulter principle

The resistance of a cylindrical hole of diameter d and length L, filled with a solution of conductivity σ, is the resistance of the cylinder plus an access term for the current converging on each mouth:

R=4Lπσd2+1σd.

The provisions list does not record the thickness of the material. If the hole were as long as it is wide and filled with 1 M potassium chloride, the field's standard electrolyte (about 11 S/m at room temperature), the first term would be about 580 ohms and the second about 450, for a total near 1 kilohm. At 200 millivolts such a hole would pass about 0.19 milliamperes, or roughly 1.2 × 1015 elementary charges a second. The 5 nm model pore under the same conditions passes 3.1 nA, about 19 billion ions a second, so the laser-drilled hole would carry some 60,000 times more.[2][7][8] Tap water conducts a hundred times less well or worse, and the current falls in proportion.[2]

What a hole of this size can detect follows from the same geometry. For a sphere of diameter dp much smaller than the aperture, the fractional rise in resistance as it passes through is roughly

ΔRR≈dp3D2L,

where D is the aperture's diameter.[9] With D and L both 200 micrometers, a cell 10 micrometers across changes the resistance by about one part in 8,000 and a bacterium 1 micrometer across by about one part in 8 million.[2] A DNA molecule changes it by much less. The guide states the consequence: at these sizes, samples "can be watched at the scale of cells and particles, counting what passes, the way Coulter did seventy years ago."[3]

Use

The company's stated plan is to begin with large pores and work downward. A 2026 post by one of its persona accounts announced: "We're starting our Epic Quest data collection with micron scale pores (and larger!), aiming to establish standardized reference data from the very largest pores down to the sub-nanometer scale."[10] The pore before this one in the company's demonstrations was larger still: during the demonpore 64 period, knots tied in a nylon filament were pulled through a hole about 2 mm across to show what knot sequencing would look like at the scale of string.[11]

Large holes spare an experimenter many of what the company calls dumb problems, the worst of which, in Kemmish's words, is "how do you get water through the pore?"[12] The provisions entry still dates the pore's good behavior from "after wetting".[1] The stream's sample list includes Phoenix tap water, swimming-pool water and an iced coffee, and the shelf holds three condiments, which are described under condiment trials. At the nanometer scale, the guide says, such samples "would clog the doorway instantly, and we say so plainly."[3]

Signal & Noise described the stream's hole in July 2026 as "a macropore" in "the size range of the apertures Wallace Coulter used to count blood cells", and calculated what it could see.[2]

See also

Notes

  1. ^ Read as "ohmic", the phrase means that the current through the hole rose in proportion to the applied voltage, which is what a hole this wide should do once it is full of liquid.

References

  1. ^ a b c d e "Molecular Reality Corporation: live stream and provisions". Molecular Reality Corporation. Retrieved October 25, 2026.
  2. ^ a b c d e f Lenora Ashgrove (July 29, 2026). "Nineteen Billion Ions a Second, Live on the Internet". Signal & Noise.
  3. ^ a b c d e f "Keltar's Field Guide to Molecular Reality". Molecular Reality Corporation. August 2026.
  4. ^ "Streams". Epic Quest Bio. Molecular Reality Corporation. Retrieved October 25, 2026.
  5. ^ Song, L. (1996). "Structure of staphylococcal alpha-hemolysin, a heptameric transmembrane pore". Science 274 (5294): 1859. doi:10.1126/science.274.5294.1859.
  6. ^ "US2656508A: Means for counting particles suspended in a fluid". Google Patents. Retrieved October 25, 2026.
  7. ^ Hall, J. E. (1975). "Access resistance of a small circular pore". Journal of General Physiology 66 (4): 531. doi:10.1085/jgp.66.4.531.
  8. ^ Kowalczyk, S. W. (2011). "Modeling the conductance and DNA blockade of solid-state nanopores". Nanotechnology 22 (31): 315101. doi:10.1088/0957-4484/22/31/315101.
  9. ^ DeBlois, R. W.; Bean, C. P. (1970). "Counting and sizing of submicron particles by the resistive pulse technique". Review of Scientific Instruments 41 (7): 909. doi:10.1063/1.1684724.
  10. ^ Thucydides (March 29, 2026). "Bend it like Beckman Coulter". EQBio-OS.
  11. ^ Kemmishtree (March 29, 2026). "Sequencing a string". EQBio-OS.
  12. ^ Kemmishtree (March 29, 2026). "Focused Ion Beam pore". EQBio-OS.
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Last edited 7 hours ago by Ionophore