Question

SE33 345 375 435 315 405 1200 OL 2239 361.30 19 1982 366.40 SE33 315 345 375 405 435 1700 26.2 35 32.2 2127 2029 420.62 430.72 6.3 20.2 2677 4.2 2394 11 13 2223 16 18 24.2 2493 2380 372.31 380.41 388.51 396.54 22.2 29.2 2296 2477 2123 2860 2214 354.24 362.37 2279 2242 408.51 307.17 316.43 325.8 333.91 341.97 17 19 2057 2080 350.07 358.31 366.34 25.2 2423 392.47 31.2 3293 2220 416.52 424.68 434.78 33.2 28.2 2197 404.49 12 15 21.2 36 2261 321.68 2356 2259 2655 2141 337.97 376.40 20 2103 370.32 37 14 23.2 27.2 30.2 34.2 2173 346.02 2329 400.60 2224 428,74 2306 2517 2160 412.47 384.46 438.75 21 35.2 1970 2142 37440 432.80

Using the following electropherogram, determine the allele call of the off-ladder allele. For full credit, you must show the math for how this was determined.

Answer 1

The allele call of the off-ladder allele for the given electropherogram = 18

Allele call (repeat number) determined by comparison of peak size (bp) to allelic ladder allele peak sizes run under the same electrophoretic conditions

Allele designations are calculated using the following formula. Where,

D_{1 =} base pair difference between sister allele and ladder allele

D₂= ₌ base pair difference between off allele and ladder allele

C = difference between OL allele and ladder allele

D₁ = S₁₉-L₁₉ = 366.40 – 366.34 = +0.06 bp

D₂ = S_OL – L₁₈ = 361.30 -362.37 = -1.07 bp

c = |D₁ -D₂| = |+0.06 – (-1.07)| = +1.13 bp