Prosecution Insights
Last updated: April 19, 2026
Application No. 18/594,870

IMAGING OF STAIN-FREE FLUORESCENCE ON WESTERN BLOT MEMBRANES WITH EXCITATION BY EPI ILLUMINATION WITH UV LEDs

Final Rejection §103
Filed
Mar 04, 2024
Examiner
SUN, CAITLYN MINGYUN
Art Unit
1795
Tech Center
1700 — Chemical & Materials Engineering
Assignee
BIO-RAD LABORATORIES, INC.
OA Round
2 (Final)
64%
Grant Probability
Moderate
3-4
OA Rounds
3y 0m
To Grant
76%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
183 granted / 288 resolved
-1.5% vs TC avg
Moderate +12% lift
Without
With
+12.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
80 currently pending
Career history
368
Total Applications
across all art units

Statute-Specific Performance

§101
1.5%
-38.5% vs TC avg
§103
47.9%
+7.9% vs TC avg
§102
17.3%
-22.7% vs TC avg
§112
28.8%
-11.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 288 resolved cases

Office Action

§103
DETAILED ACTION Response to Amendment This is a final office action in response to a communication filed on January 20, 2026. Claims 1-2, 4-8, 11-17, and 19-25 are pending in the application. Status of Objections and Rejections All rejections from the previous office action are withdrawn in view of Applicant’s amendment. New grounds of rejection are necessitated by the amendments. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim(s) 14-17 and 19-25 is/are rejected under 35 U.S.C. 103 as being unpatentable over Chan (U.S. 2019/0094511) in view of Ou (US 2015/0054979), and further in view of Yoshida (US 2003/0116723), and further in view of Swihart (US 2021/0356397). Regarding claim 14, Chan teaches an imaging system (Fig. 1A: ¶22: imaging system) comprising: a plane (Fig. 1A: the top plane of the stage 76) configured to receive and hold a block (Fig. 1A: ¶24: a sample holder 72), the plane having a first side and a second side (Fig. 1A: the top side and the bottom side of the stage 76); a camera (Fig. 1A; ¶25: image detector 68) configured to image the block on the plane (¶25: any device for collecting images of a sample and/or examination region); a transillumination source (Fig. 1A; ¶23: trans-illumination portion 52); and a light source (Fig. 1A; ¶23: excitation light source 66), the light source configured to illuminate the block on the plane via epi-illumination (Fig. 1B; ¶22: epi-illumination portion 54). Chan does not disclose the camera positioned above the first side of the plane; the transillumination source positioned below the second side of the plane; or the light source positioned above the first side of the plane. Here, Chan teaches the camera and the epi-illumination portion positioned below the plane (Fig. 1A: epi-illumination portion 54, detector 68) and the trans-illumination portion positioned above the plane (Fig. 1A: trans-illumination portion 52), which is opposite the recited positional relationship and these positional relationships depends on the orientation. However, Ou teaches to be able to function in the epi-illumination mode, the variable illuminator is typically located on the same side of the sample as the collecting optical element of the optical system; to be able to function in the trans-illumination mode, the variable illuminator is typically located on the opposite side of the sample as the collecting optical element of the optical system (¶62). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan by positioning the camera and the epi-illumination portion above the plane receiving the sample on the top and the trans-illumination portion below the plane as recited because they are well-known positional relationship in the art (Ou, ¶62). Here, the claimed limitations are obvious because all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results. MPEP 2143(I)(A). Chan further discloses the light of the imaging system may include optical radiation of any suitable wavelength, e.g., visible radiation, ultraviolet radiation, infrared radiation, or any combination thereof. Chan does not explicitly disclose wherein the transillumination source emits light having a wavelength in a range from approximately 250 nm to 325 nm. However, Yoshida teaches a fluorescent transilluminator for exposing an object to be irradiated to ultraviolet rays to make it fluoresce (¶2). The “ultraviolet rays (UV)” are the generic name of electromagnetic waves with wavelengths ranging from about 10 nm to 380 nm and is divided into the following 3 classes (¶10). The fluorescent transilluminator adopts the UV-B band (¶14), ranging from about 280 nm to 315 nm (¶12), which overlaps the recited range. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan by adjusting the transillumination source emits light wavelength within the claimed range because they overlaps the UV-B band that is adopted by the fluorescent transilluminator as taught by Yoshida. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I). Chan does not disclose the light source of the epi-illumination portion is an LED light source or wherein the LED light source emits light having a wavelength in a range from approximately 325 nm to approximately 400 nm. However, Swihart teaches an epi-illumination apparatus having LEDs for illuminations ([Abstract]), wherein each LED is individually operable to emit light of a predetermined color within a first range of wavelengths of about 200-about 325 nm with a peak of 280 nm for driving reactions such as a strain-free reaction (¶11). These lights are ultraviolet lights, which means light every having a wavelength between about 250 nm to about 400 nm (¶22). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan by substituting the excitation light source 66 for epi-illumination mode with the LED light sources for epi-illuminations as taught by Swihart because Swihart’s epi-illumination apparatus enables stain-free reactions induced by UV light for fluorescent sample visualization (¶22) and the substitution would generate nothing more than predictable results. MPEP 2141(III)(B). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I). Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). MPEP 2144.05(I). Regarding claim 15, Chan, Ou, Yoshida, and Swihart disclose all limitations of 14, but fail to teach wherein the LED light source emits light at a wavelength of approximately 365 nm. However, Swihart teaches an epi-illumination apparatus having LEDs for illuminations ([Abstract]), each emitting light in a range of wavelengths of about 200-about 325 nm with a peak of 280 nm for driving reactions such as a strain-free reaction (¶11). These lights are ultraviolet lights, which means light every having a wavelength between about 250 nm to about 400 nm (¶22). For example, the TCE and lysozyme solution is illuminated by a variety of light sources of different wavelengths, e.g., about 367 nm (¶41). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, Yoshida, and Swihart by adjusting the wavelength of the LED light source of epi-illumination mode as claimed because it is a UV wavelength which induces fluorescent sample visualization (¶22). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). MPEP 2144.05(I). Similarly, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). MPEP 2144.05(I). Regarding claim 16, Chan, Ou, Yoshida, and Swihart disclose all limitations of 14. Chan, Ou, and Yoshida do not disclose the imaging system further comprising a housing having a top and opposing housing first and housing second sides, wherein the top extends above and across the plane, wherein the top connects the housing first side and the housing second side, and wherein each of the opposing housing first and housing second sides extend from adjacent to the plane to an intersection with the top. However, Swihart teaches a housing of the illuminator apparatus (¶7). The housing 105 (Fig. 1) may comprise a cover for protecting an operator from electromagnetic radiation and providing color contrast/cancellation to enhance the visualization of the specimen (¶28). The LED light emission cones may be disposed on the first or second side surface of the housing 105 (Fig. 1; ¶33). A total internal reflection (TIR) layer 210 is disposed in a central space of the housing 105, and a clip 240 is disposed on inner side surfaces of the housing to surround entire perimeter of the chamber of the housing (Fig. 2; ¶34). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan and Ou by housing both sides of the plane and connecting to each other surrounding the plane as taught by Swihart because the housing, including the cover, would protect the operator from electromagnetic radiation and provide color contrast/cancellation to enhance the visualization of the specimen (¶28) Regarding claim 17, Chan teaches wherein the LED light source comprises at least one LED (Fig. 1A: excitation light source 66; further, the combined Chan and Swihart renders it obvious that the light source is a LED light source as described in claim 14). Regarding claim 19, Chan, Ou, Yoshida, and Swihart disclose all limitations of 16, but fail to teach wherein the LED light source comprises a first LED and a second LED wherein each of the first LED and the second LED are configured to illuminate the plane. However, Chan teaches a trans-illuminating green (G) LED light source positioned directly above a center point of the plane (Fig. 1A: G 62; further, the combined Chan and Swihart renders it obvious that the light source is a LED light source as described in claim 14). Further, Swihart teaches LEDs generating epifluorescence (EPI) illumination comprising ultraviolet (UV), blue, green, and red or a combination of these colors to image various types of gel samples (¶47). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, Yoshida, and Swihart by substituting the excitation light source of epi-illumination portion (Chan, Fig. 1A: 66) with one having two LED light sources, e.g., blue and red, as taught by Swihart to image various types of gel samples (¶47). The combined Chan, Ou, Yoshida, and Swihart would necessarily have two epi-illuminating LEDs configured to illuminate the plane. Here, the claimed limitations are obvious because all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results. MPEP 2143(I)(A). Chan, Ou, Yoshida, and Swihart do not disclose the first LED positioned on the housing first between the plane and the intersection of the housing first side with the top or the second LED positioned on the housing second side between the plane and the intersection of the housing second side with the top. However, Swihart teaches a housing of the illuminator apparatus (¶7). The housing 105 (Fig. 1) may comprise a cover for protecting an operator from electromagnetic radiation and providing color contrast/cancellation to enhance the visualization of the specimen (¶28). The LED light emission cones may be disposed on the first or second side surface of the housing 105 (Fig. 1; ¶33). A total internal reflection (TIR) layer 210 is disposed in a central space of the housing 105, and a clip 240 is disposed on inner side surfaces of the housing to surround entire perimeter of the chamber of the housing (Fig. 2; ¶34). Thus, the combined Chan, Ou, Yoshida, and Swihart would have each of the two epi-illuminating LED light source between the plane and the intersection of the housing, either first or second side, with the top (i.e., the cover). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, Yoshida, and Swihart by positioned the two LEDs on the housing and between the plane and the intersection of the housing, either first or second side, with the top as taught by Swihart because all the claimed elements were known in the prior art and the combination would not change their functions but yield nothing more than predictable results. MPEP 2143(I)(A). Regarding claim 20, Chan, Ou, Yoshida, and Swihart disclose all limitations of 19, but fail to teach wherein a first centerline of the first LED forms a first angle of between approximately 10 degrees and approximately 25 degrees with the first side of the plane, and wherein a second centerline of the second LED forms a second angle of between approximately 10 degrees and approximately 25 degrees with the first side of the plane. However, Swihart teaches a side-lit transillumination assembly (¶36) with a plurality of individually addressable sets of LEDs, each set emitting light of one color (¶36). A deliberately applied light-scattering pattern can be formed so that the light incident on elements of the pattern will not be reflected (when incident angle > TIR angle) and will be emitted toward the sample (¶36). The specific required angle would be adjusted to ensure the emitted light to be toward the sample. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, Yoshida, and Swihart by adjusting the angle between the centerline of each LED and the first side of the plane within the claimed range through routine experimentation to ensure the emitted light to be toward the sample. MPEP 2144.05 (II)(B). Regarding claim 21, Chan, Ou, Yoshida, and Swihart disclose all limitations of 16, including wherein the LED light source is positioned on the top (Chan, Fig. 1A; Ou, ¶62) and is configured to illuminate the plane (Chan, Fig. 1A; ¶21: epi-illumination mode). Regarding claim 22, Chan, Ou, Yoshida, and Swihart disclose all limitations of 21. Chan, Ou, and Yoshida do not disclose wherein the LED light source comprises a first LED and a second LED, wherein each of the first LED and the second LED are positioned on the top and are configured to illuminate the plane. However, Swihart teaches LEDs generating epifluorescence (EPI) illumination comprising ultraviolet (UV), blue, green, and red or a combination of these colors to image various types of gel samples (¶47). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, and Yoshida by substituting the excitation light source of epi-illumination portion (Chan, Fig. 1A: 66) with two LED light sources, e.g., blue and red, as taught by Swihart to image various types of gel samples (¶47). The combined Chan, Ou, Yoshida, and Swihart would necessarily have two epi-illuminating LEDs and both are positioned on the top (as the epi-illumination portion) and configured to illuminate the plane. Regarding claim 23, Chan, Ou, Yoshida, and Swihart disclose all limitations of 21, but fail to teach wherein the LED light source is positioned directly above a center point of the plane. However, Chan teaches a trans-illuminating green (G) LED light source positioned directly above a center point of the plane (Fig. 1A: G 62). Further, Swihart teaches LEDs generating epifluorescence (EPI) illumination comprising ultraviolet (UV), blue, green, and red or a combination of these colors to image various types of gel samples (¶47). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, Yoshida, and Swihart by substituting the green LED of trans-illumination with one epi-illumination portion as taught by Swihart because epi-illumination is an alternative illumination way to image the examination region and for example, green LED of epi-illumination would be tailored to specific types of gel sample (¶47). Here, the claimed limitations are obvious because all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results. MPEP 2143(I)(A). Regarding claim 24, Chan, Ou, Yoshida, and Swihart disclose all limitations of 14, including wherein the LED light source (Fig. 1A: excitation light source 66; further, the combined Chan and Swihart renders it obvious that the light source is a LED light source as described in claim 14) is positioned offset from a center point of the plane (Fig. 1A). Regarding claim 25, Chan, Ou, Yoshida, and Swihart disclose all limitations of 24, but fail to teach wherein a centerline of the LED light source is pointed toward a position offset from a lateral midline of the plane. However, Chan teaches the epi-illuminating light source (Fig. 1A: 66) is pointed toward a beam-splitter (Fig. 1A: 90) so that a portion of the light is pointed toward a lateral midline of the plane (Fig. 1A). Alternatively, the light path may be from a source (Fig. 11; ¶55: 144) to the examination region (Fig. 11: 56). The light travels from source 144 to mirror 162, which reflects the light toward the beam-splitter 156, so that a portion of the reflected light would toward a reflective diffuser 80b and then reflected toward the examination region 56 (Fig. 11; ¶56). In Fig. 11, the centerline of the light source 144 is pointed towards apposition offset from a lateral midline of the plane. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Chan, Ou, Yoshida, and Swihart by incorporating a mirror and a reflective diffuser as taught in Fig. 11 of Chan to substitute the light path of the epi-illumination via a beam-splitter shown in Fig. 1B of Chan because it would enable autofocusing (¶55). Here, the claimed limitations are obvious because all the claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination yielded nothing more than predictable results. MPEP 2143(I)(A). Response to Arguments Applicant’s arguments have been considered but are moot in light of new grounds for rejection. The newly cited reference, Yoshida, is now relied on to teach the newly added limitation “wherein the transillumination source emits light having a wavelength in a range from approximately 250 nm to 325 nm.” Conclusion THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to CAITLYN M SUN whose telephone number is (571)272-6788. The examiner can normally be reached M-F: 8:30am - 5:30pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan Van can be reached on 571-272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /C. SUN/Primary Examiner, Art Unit 1795
Read full office action

Prosecution Timeline

Mar 04, 2024
Application Filed
Oct 15, 2025
Non-Final Rejection — §103
Jan 15, 2026
Applicant Interview (Telephonic)
Jan 15, 2026
Examiner Interview Summary
Jan 20, 2026
Response Filed
Feb 17, 2026
Final Rejection — §103 (current)

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Prosecution Projections

3-4
Expected OA Rounds
64%
Grant Probability
76%
With Interview (+12.3%)
3y 0m
Median Time to Grant
Moderate
PTA Risk
Based on 288 resolved cases by this examiner. Grant probability derived from career allow rate.

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