Capillary Slide ROI — 2026-08-21

Analysis of 80 µm capillary slide images to determine the effective molar absorptivity of BPB (Bromophenol Blue) in the green channel under TRITC illumination (Olympus IX71, 4× objective). Four BPB concentrations (12.5%, 25%, 50%, 100% stock) imaged; Beer-Lambert fit gives ε_eff for use in stepped-channel height estimation.

Region of Interest

ROI: rows 700:1100 · cols 1050:1900 · 400 × 850 px · full image 3072 × 2048 px

Saturation Check — Raw 16-bit Green Channel in ROI

Condition	File	Min	Max	Mean	% Saturated
dark	`TS-20260821100913998998.tif`	0	3480	16	0.0%
dark	`TS-20260821100914093093.tif`	0	3164	16	0.0%
dark	`TS-20260821100914236236.tif`	0	2915	16	0.0%
dark	`TS-20260821100914376376.tif`	0	2602	16	0.0%
dark	`TS-20260821100914515515.tif`	0	3670	16	0.0%
light	`TS-20260821100903885885.tif`	38636	45561	43315	0.0%
light	`TS-20260821100904037037.tif`	36901	45331	43316	0.0%
light	`TS-20260821100904181181.tif`	37172	45318	43316	0.0%
light	`TS-20260821100904309309.tif`	37596	45284	43315	0.0%
light	`TS-20260821100904405405.tif`	38933	45371	43317	0.0%
12.5%	`TS-20260821101901816816.tif`	35789	43360	41297	0.0%
12.5%	`TS-20260821101901967967.tif`	36708	43543	41297	0.0%
12.5%	`TS-20260821101902097097.tif`	37302	43509	41299	0.0%
12.5%	`TS-20260821101902237237.tif`	37447	43388	41297	0.0%
12.5%	`TS-20260821101902380380.tif`	36793	43329	41297	0.0%
25%	`TS-20260821102115012012.tif`	31074	41992	39910	0.0%
25%	`TS-20260821102115108108.tif`	32300	42194	39910	0.0%
25%	`TS-20260821102115204204.tif`	31215	41930	39909	0.0%
25%	`TS-20260821102115296296.tif`	31553	42099	39911	0.0%
25%	`TS-20260821102115393393.tif`	32045	42216	39908	0.0%
50%	`TS-20260821102315571571.tif`	33406	39472	37343	0.0%
50%	`TS-20260821102315773773.tif`	34357	39361	37345	0.0%
50%	`TS-20260821102315868868.tif`	33083	39426	37344	0.0%
50%	`TS-20260821102315963963.tif`	33969	39475	37346	0.0%
50%	`TS-20260821102316102102.tif`	33221	39508	37344	0.0%
100%	`TS-20260821102525821821.tif`	27134	34976	32757	0.0%
100%	`TS-20260821102525923923.tif`	25997	34795	32758	0.0%
100%	`TS-20260821102526015015.tif`	24668	35052	32756	0.0%
100%	`TS-20260821102526112112.tif`	26251	35071	32759	0.0%
100%	`TS-20260821102526627627.tif`	25387	35347	32755	0.0%

Condition

File

Min

Max

Mean

% Saturated

dark

TS-20260821100913998998.tif

3480

0.0%

dark

TS-20260821100914093093.tif

3164

0.0%

dark

TS-20260821100914236236.tif

2915

0.0%

dark

TS-20260821100914376376.tif

2602

0.0%

dark

TS-20260821100914515515.tif

3670

0.0%

light

TS-20260821100903885885.tif

38636

45561

43315

0.0%

light

TS-20260821100904037037.tif

36901

45331

43316

0.0%

light

TS-20260821100904181181.tif

37172

45318

43316

0.0%

light

TS-20260821100904309309.tif

37596

45284

43315

0.0%

light

TS-20260821100904405405.tif

38933

45371

43317

0.0%

12.5%

TS-20260821101901816816.tif

35789

43360

41297

0.0%

12.5%

TS-20260821101901967967.tif

36708

43543

41297

0.0%

12.5%

TS-20260821101902097097.tif

37302

43509

41299

0.0%

12.5%

TS-20260821101902237237.tif

37447

43388

41297

0.0%

12.5%

TS-20260821101902380380.tif

36793

43329

41297

0.0%

25%

TS-20260821102115012012.tif

31074

41992

39910

0.0%

25%

TS-20260821102115108108.tif

32300

42194

39910

0.0%

25%

TS-20260821102115204204.tif

31215

41930

39909

0.0%

25%

TS-20260821102115296296.tif

31553

42099

39911

0.0%

25%

TS-20260821102115393393.tif

32045

42216

39908

0.0%

50%

TS-20260821102315571571.tif

33406

39472

37343

0.0%

50%

TS-20260821102315773773.tif

34357

39361

37345

0.0%

50%

TS-20260821102315868868.tif

33083

39426

37344

0.0%

50%

TS-20260821102315963963.tif

33969

39475

37346

0.0%

50%

TS-20260821102316102102.tif

33221

39508

37344

0.0%

100%

TS-20260821102525821821.tif

27134

34976

32757

0.0%

100%

TS-20260821102525923923.tif

25997

34795

32758

0.0%

100%

TS-20260821102526015015.tif

24668

35052

32756

0.0%

100%

TS-20260821102526112112.tif

26251

35071

32759

0.0%

100%

TS-20260821102526627627.tif

25387

35347

32755

0.0%

Beer-Lambert Analysis

Stock solution: 0.05% w/v BPB · M_W = 669.96 g/mol · C_stock = 0.7463 mM
Path length: 80 µm
I_dark = 0.138 · I_light = 676.181 (dark-corrected, 10-bit means)
ε_eff mean = 2.33997 L mol⁻¹ µm⁻¹ · ε_eff fit = 2.08346 L mol⁻¹ µm⁻¹ · R² = 0.989702

Conc. (mM)	I dark-corr. (10-bit)	T	A = −log₁₀(T)	ε_eff (L mol⁻¹ µm⁻¹)
0.0933	644.64	0.95336	0.02074	2.77964
0.1866	622.95	0.92128	0.03561	2.38558
0.3732	582.88	0.86201	0.06449	2.16013
0.7463	511.20	0.75601	0.12147	2.03453

Conc. (mM)

I dark-corr. (10-bit)

A = −log₁₀(T)

ε_eff (L mol⁻¹ µm⁻¹)

0.0933

644.64

0.95336

0.02074

2.77964

0.1866

622.95

0.92128

0.03561

2.38558

0.3732

582.88

0.86201

0.06449

2.16013

0.7463

511.20

0.75601

0.12147

2.03453

Calibration saved to notebooks/2026-08-21_blue_dye/capillary_slide_calibration.json